


vinculum

by Skadiseven



Category: Star Trek, 陈情令 | The Untamed (TV), 魔道祖师 - 墨香铜臭 | Módào Zǔshī - Mòxiāng Tóngxiù
Genre: Aliens!, Alternate Universe, Alternate Universe Star Trek, Body Swap, Established SongXiao, Ice Cream, M/M, Of many varieties and positions, Sex, Space!, Swordfighting, USS Titan, background wangxian - Freeform, dorks in space, nuisance to lovers, planets!, pretty rocks, songxiao - Freeform, sort of dubcon? hard to figure out with body swapping, star trek typical shenanigans
Language: English
Status: Completed
Published: 2020-12-13
Updated: 2020-12-13
Packaged: 2021-03-10 16:27:36
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 21,278
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28010139
Author URL: https://archiveofourown.org/users/Skadiseven/pseuds/Skadiseven
Summary: “There was a transporter accident,” Lieutenant Commander Palmer explains. “The solar flare...well we think the solar flare interfered with the transport. You, Xiao, and Xue were...scrambled. Right now, your consciousness is in Xiao’s body, Xue is in your body, and Xiao is in Xue’s body. We are...working on a solution.”Meaning, Zichen thinks numbly, they have no fucking clue what to do.It would be one thing to be body swapped with Xingchen. Weird, but not awful. But Zichen keeps getting stuck as the annoying Ensign Xue Yang, and sometimes Xingchen is Ensign Xue. And sometimes they’re him. It’s confusing and frustrating and he really, really,reallyjust wants to be normal human Zichen again.Normal Zichen in love with Xingchen.That’s it.He has no interest in whatever Ensign Xue is doing with his life.None.
Relationships: Sòng Lán | Sòng Zǐchēn/Xiǎo Xīngchén, Sòng Lán | Sòng Zǐchēn/Xiǎo Xīngchén/Xuē Yáng | Xuē Chéngměi
Comments: 44
Kudos: 101
Collections: Songxuexiao Exchange 2020





	1. vinculum

**Author's Note:**

  * For [keiyashi](https://archiveofourown.org/users/keiyashi/gifts).



> There is really only one chapter. Chapter 2 is a Star Trek primer specific to this story, in case you want to know more about cetacean ops and whatnot.
> 
> Thanks so much to @kevinkevinson, @rynleaf, @coslyons and @cirilien for the exceptional beta reads, and many thanks to the other Star Trek people I consulted and yelled to about this story.
> 
> All that having been said, I really tried to make it accessible to anyone, even with only a passing knowledge of Star Trek, so don't let that throw you off.

_noun_   
_vin·cu·lum | \ ˈviŋ-kyə-ləm_   
_1\. A unifying bond._   
_2\. In mathematics, a horizontal line placed above multiple quantities to indicate that they form a unit._

★ ★ ★

There are no two ways about it. Xiao Xingchen is going to be the death of him. As far as Song Zichen knows, no one has ever died of exasperation, but it’s almost 2400. It has to happen eventually.

“But _why_ are you putting rocks in your pockets?” Zichen begs. “For that matter, where did you even get pockets?”

“Cetacean Ops, Zichen,” Xingchen says patiently, as though there could be nothing more obvious.

Zichen tries desperately to understand if this is an answer to the rocks question or the pockets question. Or both. Or neither. With Xingchen, it could be anything.

“I’m sure the dolphins have enough rocks,” he says, guessing hopefully. “If rocks are even a thing they need. We are going to be late to the rendezvous point, and in case you hadn’t noticed, Starfleet is not big on tardiness, especially when there’s an impending solar flare.”

Xingchen crouches, selecting a wide, flat rock that glitters with black specks. He holds it up to the piercing light of the planet’s two suns, examining it carefully. Whatever his VISOR tells him makes his face light up, and Zichen softens. He can never resist Xingchen’s enthusiasm for his hobby of the week. But he tries again, because as much as he loves Xingchen, he does not particularly want to be stuck on Kryal IV with him, even for another hour.

“I will throw you over my shoulder and carry you,” he threatens, ultimately useless because Xingchen just laughs and continues staring at the ground.

Zichen gives up.

“Okay, what are you looking for? I’ll help,” he says, bending down and peering at the rocks Xingchen has apparently found the most compelling on a planet covered in rocks that all look exactly the same.

“Fuck, you are _whipped_.”

Zichen resists the urge to roll his eyes at the unwelcome voice behind him. The owner of the voice is always unwelcome, and yet somehow continues to show up, barging into every conversation unwelcomingly. It is truly astounding how good he is at being unwelcome. An unwelcome gift, as it were.

“I’m devastated. Did you think of that insult just now, _Ensign_ , or have you been working on it all day?” Zichen asks the still-unwelcome security ensign as Xingchen points to a rock by Zichen’s foot, a pink stone that’s shaped like a heart.

“I had plenty of time to think of it, _Lieutenant_ , considering you’re fucking late.”

Zichen is annoyed that the Orion is right. No Orion should ever be right. Especially not this one.

“Xue Yang, hand me that rock and we can leave,” Xingchen says with a cheerful grin, pointing at a grey stone that looks like a shard of Earth shale, and the little green pirate frowns irritably.

It is ungenerous of him, but Zichen savors Ensign Xue’s internal debate. He has obviously been tasked with retrieving them for transport off the planet, but he doesn’t want to come across as, in his words, whipped. A gentleman would not gloat at the quandary. Zichen raises an eyebrow and waits to see what Ensign Xue will do.

“All you have to do is ask, Xiao. I’ll give you anything you want,” Ensign Xue retorts with a smug smirk at Zichen.

Zichen mentally rolls his eyes. He really should have seen that coming. Ensign Xue seems to only have two modes: hostility or flirtation.

Typical Orion.

Ensign Xue lobs the rock at Xingchen who deftly catches it despite his blindness, and shoves it in yet another hidden pocket. Zichen is going to have to find out where Xingchen is getting his uniforms tailored.

They follow Ensign Xue back to the pattern enhancement beacons, set on the top of a hill. It isn’t usually necessary, but Kryal IV has a unique electromagnetic signature that sometimes interferes with a clean transporter signal. Xingchen slips his hand into Zichen’s and leans toward him.

“I told the quartermaster that pockets were a Bajoran religious necessity. How else will we carry around our sacred relics?” he whispers conspiratorially, and Zichen chokes on his laughter.

“Junior Lieutenant Xiao Xingchen, are you a _blasphemer_?” he whispers back, delighted by Xingchen’s failing attempt to look innocent.

“It could be true,” Xingchen insists, and the corner of his mouth quirks in mischief. “No one has ever asked for proof.”

Zichen looks at that tiny hint of a smile and falls in love all over again, as he has nearly every day since Xingchen was assigned to the USS Titan three years ago. Zichen, only a junior lieutenant then, had been his orientation liaison. He had taken one look at the tall, gorgeous Bajoran medical ensign, the evanescent wave of his mouth flickering between awe and solemnity as he looked around the docking bay, and had known he was utterly ruined for anyone else ever again.

“Pretty sure this is the worst assignment I’ve ever had,” Ensign Xue complains. “Are you always this domestic and boring or is this a special treat just for me?”

Ensign Xue, on the other hand, has been a noisy sword in Zichen’s side for months, since being unfortunately assigned to engineering. The only good thing Zichen can say about him is that he always shows up on time. Zichen has doubts about the likelihood of him having any other skills. Glancing at the slight, almost delicate, black-haired Orion who somehow always manages to look like he slept in his uniform, Zichen thinks even he could beat Ensign Xue in a fight.

“Definitely you. We think about annoying you all the time. Just this morning, I woke up and thought, ‘how can I irritate unnamed security officer number two?’” Zichen retorts, picking up speed to reach the rest of the crew on the apex of the hill before he has to listen to Ensign Xue say anything else.

While the transport technician fine-tunes the beacons to send the landing party back to the Titan, Zichen tightens his fingers around Xingchen’s and looks up.

The sky over Kryal IV is the only beautiful thing about the planet, shifting between reds and oranges and golds in a constant sunset, a side effect of metallic salts in the planet’s atmosphere. Zichen can almost imagine it’s just the two of them under the fiery blanket of this magical place.

“Lieutenant? We’re ready for you to beam up,” the technician interrupts, and Zichen steps into the center of the stabilization array with Xingchen and, annoyingly, Ensign Xue.

As the ranking officer, Zichen taps his communicator and tells the transporter chief, Lieutenant Commander Palmer, “Three to beam up. Energize,” as the sky suddenly, inexplicably erupts into flame.

_no too soon it’s too soon_

_screaming screaming laughter and screaming_

_it’s never hurt before why does it hurt_

Green and purple flares scratch tracks across Zichen’s vision, and he only has a second to be surprised at how much dying feels exactly like he’s always known it would, as everything goes thankfully, blessedly black.

★ ★ ★

“Lieutenant? Are you awake?”

_He dreams of a planet covered in trees. He dreams of waterfalls. He dreams of moons, five moons spinning in the sky, trekking their way through the night._

“Lieutenant Song, I’m going to need you to stay calm.”

_He dreams of laying in a bed of wildflowers and breathing in their heady perfume, the girlish sound of laughter ringing in his ears._

Calm?

Zichen surrenders to consciousness and opens his eyes, blinking against the light. All he can see is light.

Oh. He’s alive.

Well.

That’s something.

“Do you remember what happened?”

The woman’s voice is on his left, and he turns slowly, expecting the light to resolve into a person or a shape, something familiar, but it doesn’t. _It doesn’t_.

What…

Then Zichen does remember. The solar flare was early and he had looked up as the coronal mass ejection slammed into Kryal IV’s atmosphere. He must...he must be blind. He would have thought being blind would be darker, though.

“Am I blind?” he croaks painfully.

There is a meaningful pause.

Ah. Zichen mourns briefly for the things he’ll never see again. The sharp white peaks of the Rocky Mountains that mean he’s almost home. The vast seas of Risa. The pulsing blue light of a perfectly calibrated warp core. The red at the tips of Xingchen’s ears when he’s happy. Dogs.

But Xingchen has managed—thrived, even—all these years. Zichen will be fine. This is Starfleet. He’ll be fine.

“Yes, but...that isn’t really the issue,” the voice answers, and he finally remembers her too. Dr. Wen, the chief medical officer. He must be in sickbay.

It seems like a fairly significant issue to Zichen, and a fearful knife cuts into his gut. If being blind isn’t the issue...what is?

“Zichen, I adjusted the settings. They were a little wonky, but you should be okay to put the VISOR back on again.”

Zichen has no idea what any of that means, but he knows that voice too, and he recoils from the hand that touches his leg so casually, so confidently. “No! Don’t touch...anything.”

He tries to slide away, but of course, he’s an idiot, and he tumbles off the bed onto the floor, pain shooting up his spine as he lands awkwardly on his butt.

“Told you he’d react like that. He fucking hates me.”

Zichen freezes and then tries to stand, slipping on his feet. He needs to go, he needs to get away. He knows that voice like the back of his hand. Or rather, he knows like his own voice, because it _is_ his own voice. How is his own voice coming from across the room, and why is it swearing, and what the _fuck_ is happening?

“Lieutenant Song, sit still and let us explain.”

A piercing command stops his panicking spiral. Another voice he knows, a person he is conditioned to obey at all cost. Commander Ledrah, chief engineer, sighs, and Zichen feels her lightly touch his shoulder.

“Don’t move,” she tells him, and against all his better judgement, he sits still.

Something cold slides onto his face, covering his eyes and snapping into place at his temples. Instantly, the world resolves itself in a riot of technicolor blobs Zichen recognizes are people, sickbay, beds, medical equipment, the ceiling, the floor, a chair. It’s wild and insane and he thinks maybe he understands, although he does not in any way _understand_.

“There was a transporter accident,” Lieutenant Commander Palmer explains. “The solar flare...well we think the solar flare interfered with the transport. You, Xiao, and Xue were...scrambled. Right now, your consciousness is in Xiao’s body, Xue is in your body, and Xiao is in Xue’s body. We are...working on a solution.”

Meaning, Zichen thinks numbly, they have no fucking clue what to do. He touches the bridge of his nose and feels the nasal ridges he knows so well. One two three four five, all there, and he wants to sob hysterically. Or maybe throw up.

“I’m green,” Xingchen says in Ensign Xue’s voice, but it’s Xingchen’s tone, Zichen knows it is, the smile that always peeks out from behind his words as clear as day.

“I’m _not_ ,” Ensign Xue says mournfully, and against his will, Zichen laughs, even though he still feels on the border of tears.

He looks at both of them, and despite the fear gripping his chest like an optronic coupler, he touches the curve of the VISOR, the way it’s designed to avoid the nasal ridges of this body. He’s fascinated by how it changes his perception of the world. This is how Xingchen sees everything? As color and heat and refracted light? It’s weird and sort of beautiful, a rainbow in his eyes. He looks at himself—at Ensign Xue wearing his body—and thinks it’s truly a miracle that Xingchen likes him. He’s just an ordinary human.

“Are you okay now?” Xingchen asks, kneeling in front of Zichen, careful not to touch him even though Zichen can tell he’s itching to reach out; Xingchen always wants contact.

Zichen nods, holding out his hand. Xingchen is Xingchen, whatever body he’s in, he tells himself, and he’ll just have to get used to it. Even so, the touch twists his stomach in a fist of nausea, his subconscious rebelling as he tries to accept this new reality.

“Yeah, awesome, very heartwarming reunion, but I fucking swear, if you do anything disgusting in my body, I will make sure Lieutenant Song pays for it,” Ensign Xue snaps. “I want it back exactly as I left it, and I have _standards_.”

Dr. Wen sighs again, this time loudly and pointedly. “Until we get this fixed, you’re all staying here and no one is doing anything ‘disgusting.’ Honestly, are all males of every species like this?”

Zichen thinks he can hear Lieutenant Commander Palmer snort. She probably says yes, but he’s stopped paying attention. He hadn’t even considered that aspect of this body swap, and he can’t decide if he’s curious or horrified.

If he knows Xingchen at all, though, he knows exactly which way he’s going to land on that question.

★ ★ ★

It is quiet and dark in sickbay by the time Xingchen slides into the narrow bed next to Zichen. They’re really not made for two, and Zichen turns so they fit, making room for Xingchen—always willing to make room for Xingchen, even when it feels so wrong. This body snuggling next to his is smaller, slimmer, the muscles more compact than lean, the scent something foreign, like spice and something woodsy instead of lemon and honey.

But it’s still Xingchen.

“Did you peek at yourself...myself? I peeked! This body is so many shades of green,” Xingchen whispers, pillowing his head on Zichen’s arm. Zichen tries not to laugh out loud.

“I’ve seen you naked before. I didn’t need to peek,” he points out softly, tentatively kissing Xingchen’s forehead. In the dark, it doesn’t feel appreciably altered.

Xingchen touches a button on the VISOR, and Zichen’s visual perception changes, shifting from the bright map of the thermographic mode to blacks and greys on a sickly green background. The new night vision shows Zichen far more detail, even the shadows and planes of individual features.

“I bet Xue takes you for a test flight,” Xingchen teases. “I would, just to see what it’s like, being human.”

“Boring, I promise,” Zichen tells him, kissing the tip of his nose. It’s also more or less the same, and he ventures to kiss Xingchen’s mouth.

That’s a bit more unusual than he is immediately comfortable with, and Zichen leans stubbornly into the kiss. The mouth is a different shape, a different taste, but it’s not unacceptable. Actually, he decides, as Xingchen nibbles on Zichen’s lower lip, it’s quite pleasant. This close, he can’t really see the details of this face anyway, so it’s easy enough to pretend it’s still Xingchen’s smile, Xingchen’s cheekbones, Xingchen’s nose, Xingchen’s light brown, blank eyes.

“Is this weird for you?” he asks when Xingchen lets him breathe again. “Being on _that_ side of your body?”

“Yes, it’s fantastic,” Xingchen says, not quite answering the question. “I’ve always wondered what I was like in bed, and I plan to find out.”

Zichen groans, because Xingchen is busy making good on his curiosity, untying the loose sleep pants and pushing them down, and Zichen is, as ever, helpless to stop him.

“Ohhhh, that’s neat,” Xingchen breathes out, rubbing his thumb up the penile ridges. “I mean, obviously I’m familiar with them, but it’s such a different angle. And it’s you.”

Zichen has always thought the seven Bajoran penile ridges were an intriguing counterpoint to the ridges on Xingchen’s nose, and has, at times, casually wondered what the evolutionary purpose of them is. This is not one of those times. There is nothing casual about the way this feels. It’s more like a volcano under his skin, on the cusp of unbearably painful in its intensity. He has to slap a hand over his mouth to cover the positively shameless sounds that are trying to escape his mouth, closer to crying than moaning and louder than either.

“Have I never mentioned,” Xingchen inquires, stroking Zichen again, this time a little harder, “how good this feels?”

He has, of course, but no words could ever have done this justice. Zichen is suffering, truly _suffering_ , and Xingchen just keeps languidly moving his hand.

“I wish I could see your face right now,” Xingchen murmurs. “I never get to see what you look like when you’re wanting me. Or, I guess, what I look like when I’m wanting you.”

The wistful note in Xingchen’s voice breaks Zichen’s heart a little, and somehow makes him want him more, too much, more than he has the higher intellectual function to express.

“You look like a supernova, a star being born,” he whispers, rolling on top of Xingchen. “I can never get enough.”

Xingchen wraps his arms around Zichen’s neck and cants his hips against Zichen, shooting overwhelming sparks through his body. Zichen is completely and utterly lost. He feels like a teenager again, grinding uncontrollably against Xingchen, kissing him in a dozen haphazard places—here on his ear, here on his mouth, here in the fluttering hollow of his throat. It’s embarrassingly few minutes, possibly embarrassingly few seconds, before his climax crashes resoundingly through him, transforming him into a shuddering, shaking mess. He smothers the sound on Xingchen’s shoulder, but he’s not sure he’ll ever stop feeling the ripples of it.

Xingchen seems pleased with himself, both himselves. He pats Zichen’s cheek approvingly as Zichen attempts to recover some semblance of regular breathing.

“You wear me well,” he says, and Zichen laughs weakly.

“I want to return the favor,” he manages to rasp out, and he can see the rough outline of Xingchen shaking his head.

“You don’t have to...I know how…” Xingchen tries to argue, and Zichen shushes him.

“You’re you, in any body. I insist,” he says with a grin, and now it’s Xingchen’s turn to laugh, silvery and light.

“Well. If you insist…” Xingchen sets a hand on the top of Zichen’s head and pushes. “Get to work.”

Despite his bravado, it takes some effort. Zichen has always struggled with physical contact, especially strange physical contact, and he can’t stop thinking that he has particularly never had any interest in touching the aggravating Orion. It takes Zichen a few minutes of exploration, kissing a trail down Xingchen’s belly, using his hands to feel the different lines of this body, before he can bring himself to take the cock in his mouth. It helps to have Xingchen’s fingers in his hair—half caressing, half impatient tugging—and hear his soft gasps, sensations that are wholly familiar, wholly Xingchen.

But once he fits his mouth over the head, once he registers Xingchen’s reaction—the exhale of pleasure, the lifted hips, the tightened grip—once he gets used to the unusual, faintly-pebbled texture of the skin, once he drops into a cadence he knows of lips and tongue and love, the strangeness drops away. It is only Zichen and Xingchen, all he ever wants.

Xingchen doesn’t even bother to be quiet, and Zichen doesn’t even bother to quiet him, relishing the completely unselfconscious way he begs for more, the tantalizing moans when Zichen speeds up, and the shockingly delicious taste when he comes.

Zichen can’t help licking his lips, trying to identify the flavor, tart and sweet. He should have expected it; Orion women are adapted for sexual pleasure. It stands to reason that the men are as well.

“I can hear you thinking.” Xingchen ruffles Zichen’s hair to catch his attention “Tell me?”

In answer, Zichen settles back down next to Xingchen and cups his face, kissing him deeply.

“Welllll,” Xingchen says, and Zichen waits for more, but Xingchen just kisses him again, which is, honestly, more enjoyable than talking anyway.

“Look, I’m not saying that wasn’t super dee duper to experience second hand,” Zichen’s voice grumbles from across the room, “but either shut the fuck up so I can sleep or invite me over. So fucking inconsiderate.”

Xingchen actually giggles, and Zichen has to cover his mouth to keep him from saying anything, _anything_ at all.

“ _No_ ,” he hisses, and Xingchen retaliates by licking his palm.

Zichen can’t help chuckling, both at this impossible, ridiculous, wonderful man and the aggrieved snort from poor Ensign Xue.

“I love you,” he whispers into Xingchen’s ear and just barely hears the response against his hand, the same response as always.

“Too.”

Love makes Zichen generous. Maybe he’ll apologize to Ensign Xue in the morning.

★ ★ ★

But in the morning, Zichen doesn’t have the chance for apologies. By the time he wakes up, Lieutenant Commander Palmer and Dr. Wen are back with the chief science officer, Dr. Golwat and a solution.

Sort of.

“After some discussion, we’ve decided to replicate the circumstances of the transport without the solar flare and see if we can alter the patterns to separate you correctly,” Lieutenant Commander Palmer explains. “It’s perfectly safe.”

For some reason, Zichen is rarely comforted by Starfleet officers reassuring him that things are perfectly safe. Reluctantly, though, he has to admit, the plan does _sound_ reasonable. It was a fluke to begin with. Sending them back through the transporter should allow the technicians to realign everyone’s patterns properly.

Standing on the transporter pad, he is less enthusiastic. He’s never been afraid of transporting, _never_ , but for the first time, a knot forms in his stomach at the idea of dematerializing. What if this just makes things worse? It could make the shift permanent, degrade the pattern beyond recognition, recombine their bodies into one horrific creature, break something else he hasn’t thought of—his mind flips through an entire index of possible worst-case-scenarios. Xingchen-in-Xue waves at him cheerfully, apparently viewing this as another exciting adventure. Xue-in-Zichen refuses to look at either one of them.

Zichen abruptly realizes they’ve been in the same room with the man for three whole minutes and not had to listen to him either swear or complain. Astounding.

Transporting doesn’t feel like anything this time, which is so much better. And when Zichen is himself again, he is himself again. His own tea-dyed skin. The scar on the back of his hand from a stupid fencing mistake. He runs his fingers through his long hair, for once glad to feel the too-thick mop that never looks as presentable as he thinks it should.

Xingchen smiles at him, the right Xingchen, his Xingchen. Ensign Xue sniffs himself and makes a face.

“I need a shower,” he mutters, shooting Zichen a dirty look.

Zichen just grins. Not even Ensign Xue is going to ruin his reunion with his marvelously normal human body. He is _never_ going to complain about it ever again.

“I didn’t realize you were even acquainted with the concept. What an agreeable surprise,” he shoots back, and earns a predictable eye roll and stomping exit.

“Zichen, be nice,” admonishes Xingchen.

Zichen takes one moment to be extra proud of himself for actually considering the possibility of future benevolence, before the ship erupts in the blaring sirens and flashing lights of a shipwide red alert.

★ ★ ★

Zichen wonders if he should take Wei Wuxian’s drink away from him while he is in the middle of telling a story, or if it will only make him more prone to spilling the phosphorescent green liquid all over the table in Eleven Aft.

“You should have seen it! It was only luck that I was even on the bridge, but this huge ship materialized in front of us. Not like a Bird-of-Prey, it literally just appeared! No shimmer, no warning, nothing! And then it fired this...I don’t know...energy beam or something. Vaporized a piece of the Bussard collector dump vent. Man, it was crazy.”

Wuxian gestures with his glass, miraculously not spilling a drop. Xingchen and Zichen glance at each other. It is remarkable how often their exobiologist and weapons specialist friend manages to end up on the bridge. It probably has nothing to do with Chief Conn Officer Lan’s shifts at the helm.

“But what happened?” Xingchen asks. “Did we just...run away?”

The short answer is: yes. Even Zichen knows that much. The Titan had taken evasive maneuvers to avoid the alien weapon and gone to warp to escape being fired on again. It seems to have been successful, but it was still a mystery. No one knew why they had been attacked, or frankly, given the observed capabilities of their attackers, how had they escaped.

“Better to live and fight another day,” Wuxian says with a grin. “Or, and it pains me to say this, maybe we don’t want to fight the scary aliens with the energy beams at all.”

“That’s the stupidest thing I’ve ever heard. What’s the point of photon torpedoes, if we’re never going to use them? It’s just lazy to run. We _should_ have stayed and kicked their asses.”

Of course, Zichen thinks. Of course Ensign Xue has an idiotic opinion. The Orion is sitting at the table behind them, feet kicked up on a chair and spinning a wicked-looking black knife in his fingers. He looks far too comfortable manipulating the dangerous weapon, and Zichen’s stomach clenches inconveniently at the memory of Xingchen using Ensign Xue’s clever hands.

“It’s a good thing you aren’t tactical, then,” Zichen tries to rein in his acerbic tone. “Why risk the lives of thousands of crew if we don’t have to?”

“It’s not a risk if you win, and you don’t win if you don’t fight.” Ensign Xue’s face cracks open in a careless grin.

“Spoken like a true pirate,” Zichen mutters, and Ensign Xue flips the knife into the air, catches it, and slams it down, point first into the table.

“Damn right,” he growls, meeting Zichen’s eyes. “Since the day I was born.”

He snatches the knife from the table and stalks out of the bar.

“Zichen, you’re always so hard on him,” Xingchen says—

—at the same time Wuxian says, “What a pain in the ass.”

Wuxian and Zichen look at each other and laugh, and Xingchen shakes his head. “He’s not that bad. It must be hard to be Orion in Starfleet. We should all get to choose who we want to be without constantly having to defend where we came from.”

Fine, Xingchen has a point, one that Zichen is personally familiar with, and he feels a little bad for overlooking it before. Plus, it’s not like humans are known for their great sense and staunch morals. Zichen kisses Xingchen’s nose. “Alright. But he _is_ a pain in the ass.”

Xingchen’s mouth crooks in a smirk.

“You like one part of him well enough,” he teases.

To his neverending horror, Zichen blushes. He does not _blush_. He is a Starfleet lieutenant and a warp engineer. He does not blush.

Wuxian looks like he’s about to ask a very nosy question that Zichen absolutely does not want to answer. Instead, he jumps up and grabs Xingchen’s hand. “We’re leaving, now. Thanks for the drink, Wuxian. Fencing tomorrow? Great, see you then.”

Partly he is escaping, and partly it has occurred to him that he hasn’t yet kissed Xingchen soundly enough since they were restored to their real bodies. He is suddenly eager to remedy that oversight.

They are barely back in their quarters before Zichen is unzipping Xingchen’s uniform, biting the edge of his collarbone, sliding his hands inside his pants to squeeze the curve of his ass.

Before Xingchen, Zichen hadn’t been all that interested in sex. It was a thing people did. It was even something he did on occasion, with varying results. But after Xingchen, some days it was all he could think about. _Xingchen_ was all he could think about. He’d thought, though, that the constant, heart-stopping desire would eventually dissipate.

So far, in three years, it has not.

He has never been so glad to be wrong about anything.

Without warning, Xingchen pushes Zichen backward, knocking him back onto the bed and straddling him. His hair is tousled, his lips are red from being kissed, and he has a sinful smile on his lips. Zichen is dying to see what he does next and very purposefully ignores a sudden ache in his foot.

_he is crushed_

_yanked by pinching hands_

_his entirety siphoned through a pinprick_

Zichen is punched in the face, hard enough that tiny white lights dance in the corners of his eyes. He instinctively blocks the follow-up left-hand punch and grabs his attacker’s fist, dropping down and rolling backward, aiming his feet for the midsection and flipping the man’s body over his head. He springs lightly to his feet, but the man is already up, already running toward him, tackling him around the waist and driving him back onto the mat. Big hands pin Zichen’s shoulders.

“Do you yield?”

By now, he recognizes the man he’s sparring—Lieutenant Lan—and he should say yes, he should absolutely yield to a superior officer and a superior fighter, but logic deserts him.

The man had _punched_ him.

Zichen kicks a leg into the air and pivots his hips, throwing Lan off him and rolling, grabbing his leg with one arm, his shoulder with the other and bringing one to meet the other, leveraging all his weight to keep his opponent glued to the mat. He’s easily as tall as Lan, and probably weighs more. This should be enough to pin him.

Fuck! This isn’t his body, it’s Ensign Xue’s, and with that realization comes the memory of what he had been doing before his consciousness had been so rudely hauled across the ship and deposited inside someone else’s flesh and bones. He can feel Lan’s muscles bunching, and without waiting to see how Lan plans to catapult him across the room, Zichen is up and running.

It takes far too long to navigate all the levels to get to his quarters. The door refuses to open for him—for Ensign Xue—and it takes precious seconds to override it. He slams through before it even opens all the way.

“Xingchen! That’s not me!” he yells.

“I’m pretty sure he realizes that,” Xingchen’s face says with Ensign Xue’s smirk. “Since he is you now, and all. But hey, you borrowed me, so I figured I’d return the favor.”

Zichen struggles to process the scene, Xingchen underneath him, not underneath him, Xingchen half naked, so many clothes on the floor, he’s half naked too, but it’s not Xingchen, it’s that motherfucker, and he is touching him, no, Xingchen is touching him, they’re touching each other, and Zichen is going to _kill_ them _both_.

His arm is cocked back, furious, before Xingchen, who is now wearing Zichen’s body, is up and catching him, using his face to smile, using his strength to keep Zichen from murdering the motherfucking pirate.

“Zichen, it’s me, it was me, it’s my fault, don’t be mad. I was just curious. You don’t mind if I’m curious sometimes, remember? We talked about it. Zichen. Zichen? Love, look at me. It’s me.”

Slowly the words permeate. Slowly the fury ebbs, soothed by Xingchen’s words in Zichen’s voice, both familiar, both _known_. Slowly, the look on Xingchen’s...no...Ensign Xue’s face registers, the flickering fear. Zichen realizes he’s holding a knife, Ensign Xue’s black knife, and it fits perfectly in his hand, ready to be used.

He drops it with a clatter.

“I’m sorry. Xingchen, I’m sorry, I just...I reacted...I don’t know why…”

Zichen’s tongue is tripping over the words, and he realizes he means it. It was so much more anger than he’s ever felt before, more than he ever thought was possible, a tsunami of rage. He blinks in confusion at Xue-in-Xingchen’s almost sympathetic expression.

“Yeah, that’s sort of an Orion thing.”

Xue-in-Xingchen stands and fixes his clothes, touching the VISOR curiously. He’s still obviously hard, and Zichen tries to repress the urge to stab him again.

“Shit, is this what I look like to you?,” Ensign Xue asks Xingchen-in Zichen. “I really am hot. Mirrors just don’t capture all my infrared glory, you know?”

He stretches out a hand like he’s going to touch Zichen’s hair—his own hair—and Zichen flinches. Even though it’s technically Xingchen’s hand, he still flinches. Sometimes he hates himself, this reaction, this stupid fucking instinct and the way everyone, even Xue-in-Xingchen, looks hurt to be rejected.

“So...I’ll meet you guys in sickbay, then?” Ensign Xue asks, eyeing Zichen warily and retrieving his knife from where Zichen had dropped it.

The room is quiet for a long time. Xingchen is rubbing the back of Zichen’s neck, his forehead just touching Zichen’s, and eventually, the last of his temper falls away in a jagged exhale.

“Xingchen...I’m so sorry,” he repeats, tears stinging his eyes, and Xingchen’s lips tilt, a Xingchen expression on Zichen’s mouth.

“I know. I’m sorry too. I should have thought more carefully, but...I was already so...well…” He grins, sweet and winsome and so clearly about to ask for something. “I like this body. Maybe we don’t have to go to sickbay right away?”

Xingchen is always full of terrible ideas. Sometimes they’re terrible ideas like “let’s see what happens if we recombine cephalopod and Cyprion cactus DNA” and sometimes they’re terrible ideas like “let’s hijack bodies that don’t belong to us for an adventure before we do the responsible thing and figure out what’s happening.”

Big or small, dangerous or not, Zichen is always along for the ride.

“What would you like to do with my body?” Zichen asks, certain he knows the answer.

Xingchen’s smile is quick and wide, and it makes Zichen’s face look boyish and sweet. He can’t help cupping Xingchen’s cheek, and he notices that this hand, his left hand, is missing the pinky. He hadn’t realized Ensign Xue was missing a finger.

“See Bajor,” Xingchen says promptly, surprising Zichen. “I know, you were probably expecting something more indecent, but I haven’t seen it since I was a boy. And we have all these holodecks...I just thought...might as well? While I can?”

“We can see Bajor,” Zichen agrees. He hadn’t even thought about what it must be like for Xingchen to see again. “We can do anything you want.”

Zichen and Xingchen sit in the grass at the base of a roaring waterfall and eat sandwiches.

They lounge on warm rocks at the top of the Cliffs of Undalar and watch the five-moon rise of a Bajoran sunset.

And then they lay on the beach of one of the southern islands and do something positively, delightfully, wickedly indecent.

Ensign Xue looks annoyed when they finally make it to sickbay, but Xingchen just smiles at him.

“We visited Bajor,” he says with a lopsided grin, and Zichen is forced to admit that Ensign Xue seems to understand immediately, shrugging carelessly.

“Only you would waste time visiting a planet you’ve already been to.”

But there’s no rancor in the words, only a sort of fond mocking that galls Zichen for reasons he can’t put a finger on and doesn’t care enough about to determine.

★ ★ ★

Command’s response to the evident failure of permanently restoring Zichen, Xingchen, and Ensign Xue is to try again. Exactly the same way. Lieutenant Commander Palmer does apologize, but there is a protocol to follow, so Zichen resigns himself to the likelihood that he’ll find himself green or Bajoran again soon. He hopes it isn’t too inconvenient.

For two days, nothing unexpected happens. Zichen oversees the recalibration of the KLS stabilizer, Xingchen tells him about an appalling research project he and Wuxian are embarking on—attempting to grow sentient plants—and Ensign Xue glowers silently from his corner in engineering.

Actually, that _is_ a little unusual. Ensign Xue usually can’t stop talking, alternating between grumbling inappropriately about everything and flirting inappropriately with everyone who walks by. Well, everyone except Zichen. He’s never even tried flirting with Zichen, which has always been a relief.

The unexpected thing that happens is far more unexpected than—well, than he expected.

The alien ship finds them.

This time they are having dinner in Eleven Aft when Xingchen grabs Zichen’s arm at the same time someone else screams. The ship looms outside, more than twice their size, closer to three times their size, filling up the view from the bank of windows. It looks almost organic, an elegantly-curved seed pod in space, and as he watches, a luminous blue light begins to glow around the lateral line of the ship, illuminating overlapping scales, like a silvery fish in the sky. It must be their weapon, he thinks.

Before he has time to wonder what kind of ship has scales, the red alert comes on, a bright and sparkling disco party, until the meaning sinks in, and the entire bar moves in unison, a single body with a well-honed response. Zichen and Xingchen run to their stations, the same as everyone else, holding on for balance as the ship tilts and careers, presumably dodging weapons’ fire.

Zichen gets to engineering just as the sense of impending warp washes over him, the waves of matter and antimatter glowing with anticipation as they’re forced into the intermix chambers. Zichen never gets tired of hearing it.

As before, the red alert ends when the aliens don’t follow. As before, there is no explanation. As before, it’s easy to dismiss and forget.

Especially since the next day, Zichen wakes up blind and in pain. Again.

And in bed with a stranger.

“Morning, love,” his voice says from next to him, and even if Zichen didn’t _know_ it was Ensign Xue, he would have known by the way Ensign Xue manages to twist the words in his mouth, making the endearment sound scornful.

“Get out,” Zichen orders, fumbling at the bedside table for the VISOR, and Ensign Xue barks a laugh.

“You sure about that? Your boyfriend didn’t seem to mind. We’ve probably got three or four more minutes until he gets here.”

Ensign Xue sounds thoughtless and bored, but when Zichen finally gets the VISOR on, the expression on Ensign Xue’s face seems to be speculative, as if trying to gauge what Zichen is thinking. Zichen doesn’t know what game Ensign Xue is playing, but he doesn’t want to be a part of it.

“He doesn’t mind. I do. Out,” he repeats, and Ensign Xue frowns, but not exactly the way Zichen was expecting. More troubled than irked.

Or maybe Zichen is misreading the expression. It’s hard to tell in this body.

“Whatever, human,” he says with an airy wave of his hand, crossing paths with Xingchen-in-Xue in the doorway.

“Xue Yang!” Xingchen sounds pleased to see Ensign Xue, as though he didn’t know he’d be here. “Stay for a minute. I’ll find you some of Zichen’s clothes, and we can go to sickbay together.”

Ensign Xue pauses just long enough to predictably argue.“I don’t stay where I’m not wanted, Xiao.”

Zichen huffs in disbelief.

“Fuck off, human,” Ensign Xue snipes, somewhat ironically, in Zichen’s opinion, since Ensign Xue is the human at the moment.

Xingchen catches his hand. “Xue. Stay. Just for a minute.”

To Zichen’s great surprise, Ensign Xue stops, crossing his arms and hovering by the door, staying just long enough to accept the uniform Xingchen hands him before stalking away.

“He thinks you hate him,” Xingchen tells Zichen, waiting for Zichen to put on the blue medical uniform.

Zichen stuffs his hands in the pockets and finds a small, purple rock.

“I don’t hate him,” Zichen says with a shrug. “I don’t think about him at all.”

Xingchen tips his head and studies Zichen’s face.

“Of course not, love,” he says, somewhat enigmatically, before Zichen takes his hand and they head back to sickbay together.

★ ★ ★

It is the start of a very tiresome two weeks. Zichen feels like nothing more than an immunocytic gel worm or an Earth guinea pig. If one more person leans over him and says, “Hmm,” he is going to break something significant. He hasn’t felt this scrutinized since he started at Starfleet Academy, and he doesn’t like it any more now than he did then.

First, the realignment team—yes, they now have a team working on this apparently fascinating and unprecedented scientific conundrum—decides to leave the three of them in their current configuration to see if they will revert naturally.

At first, Zichen merely dislikes being trapped in someone else’s body, even if it’s Xingchen’s. And then, he really hates it because it occurs to him that perhaps Ensign Xue wasn’t wrong to be peeved that Zichen and Xingchen had used his body used for sex without permission. Xingchen looks disappointed when Zichen points it out, but agrees that it might be uncivilized behavior.

The only upside to this particular configuration is that Zichen rather likes the VISOR. It has so many settings, and he spends a fair amount of time investigating its capabilities.

“Did you know you could detect lying with a combination of thermal and electromagnetic modes?” he asks Xingchen.

“Of course I did,” Xingchen promptly lies.

“Liar,” Zichen grins, and Xingchen grins back, curving the deep-green-almost-black lips into something lascivious that sends a shiver up Zichen’s back.

While he wouldn’t exactly call it an upside, Zichen is finding himself less averse to Ensign Xue’s body, at least when Xingchen is wearing it. He’s even starting to like his— _the_ body’s smile.

After two days spent as Zichen-in-Xingchen, Xingchen-in-Xue, and Xue-in-Zichen, the only thing of significance that happens is that they shift, somewhat painfully, into Zichen-in-Xue, Xingchen-in-Zichen, and Xue-in-Xingchen. The realignment team determines that a natural solution will not be forthcoming, although they are intrigued to discover that Zichen is the only one who experiences pain before the shift. Zichen is less intrigued.

“Maybe it’s just because I’m human,” he suggests after a barrage of tests with no conclusive result. He is not going to give them another reason. He refuses to believe there is any other reason.

They decide to try replicating the circumstances of the first switch, including the solar flare. On the upside, a suitable planet—Yecal VI—is found nearby with a predictable solar flare cycle. On the downside, the next flare is a day away, and Zichen has to spend twenty-one more dreadful hours small and green. He doesn’t sleep well as Ensign Xue, always dreaming of a pink sky over bluish trees, a sight that fills him with an unease he doesn’t understand.

Another downside is that he finds Ensign Xue and Xingchen in sickbay together and realizes that they are, in a way, friends. He isn’t spying, not exactly. He just doesn’t immediately announce his presence and they don’t immediately notice him.

Ensign Xue is sitting on an exam table in front of Xingchen, swinging his legs while Xingchen peers at a medical tricorder and touches buttons on the side of the VISOR.

“I’m sorry I haven’t calibrated this for a few days,” Xingchen says. “I was so busy getting used to working without the VISOR that it slipped my mind.”

“Anytime you want it back, Xiao, it’s all yours,” Ensign Xue says flippantly, and he seems different than usual, teasing and relaxed, free of his usual pinched hostility.

Xingchen’s laugh sounds like music in the midst of beeping computers and softly whirring machines. “There are benefits to Zichen’s body that I am enjoying for the time being.”

“Seems like a perfectly ordinary human to me,” Ensign Xue snorts.

Zichen considers throwing a microscope at him.

“Oh, but he’s not, is he?” Xingchen asks softly. He steps forward, forcing Ensign Xue to shift his legs so he can stand between them and adjust something on the nose of the VISOR. “Neither of you is ordinary at all.”

Ensign Xue looks away. “Shut up, Xiao,” he mutters and doesn’t say another word until Xingchen pats him on the leg and tells him the calibration is done.

It’s perfectly innocent. Zichen knows it’s perfectly innocent.

It’s sweet, actually. Zichen knows it’s sweet.

But the feeling that he’s missed something important in their conversation unsettles him anyway, like knowing he’s overlooked a single mathematical error in pages of computations—a shifted decimal or a transposed number. He’s so close to understanding, but it’s just out of reach.

When they reach Yecal VI, they are carefully monitored through the transportation process, and once again, it appears their affliction has been fixed. Zichen crosses all of his fingers and toes, prays to every god he doesn’t believe in—and a few he’s not as certain about—that this time, everything will stay normal. _Normal_.

He’s never wanted to be normal so badly in his life.

★ ★ ★

But of course, they aren’t so lucky.

In another three days, the realignment fails, much to the shock of every doctor, scientist, and transportation officer who had studied the transportation logs and found no errors. However this time, only Zichen and Ensign Xue switch. The scientists are all a-flutter at this new permutation of conscious-swapping. Zichen considers the ramifications of ejecting scientists into the vacuum of space.

“Since Junior Lieutenant Xiao appears to have stabilized, we’re just going to transport the two of you this time. The solar flare seems to have worked, so we’re going to try that again. Unfortunately, we’ll need to go back to Yecal VI, which is two days in the other direction.” Lieutenant Commander Palmer explains, and it takes every ounce of willpower Zichen has not to scream. He doesn’t want to be stuck in someone else’s body for another hour, much less two days.

Strangely, though, it hardly disrupts their lives at all. Even with the missing finger, Xue’s hands are nimble and dexterous enough to do Zichen’s engineering tasks. And Zichen’s body is capable of being Starfleet security, although it is unnerving to have himself watching him.

“Any particular reason you’re being creepy today?” Zichen finally asks.

“Honestly, I can not stop looking at my own ass,” Ensign Xue replies, and it startles an unwilling laugh from Zichen.

After spending so much time in this body, Zichen has figured out what Ensign Xue had meant by _sort of an Orion thing_. It seems that Orion physiology is far more emotionally unpredictable, swinging high and giddy sometimes, blindly furious sometimes, and painfully yearning sometimes. It’s not even want directed at anything. It’s just greed and desire all mixed up with the frustration of not knowing _why_.

Therefore, Zichen feels perfectly justified in blaming his current body for the words that come out of his mouth.

“Xingchen can’t either.”

Ensign Xue’s jaw drops. He looks like he has suddenly lost his footing on unstable ground and tumbled into a pool of deep water.

Or, Zichen realizes with an internal groan, like he is about to say something horribly inappropriate.

“Huh. Would’ve pegged you two the other way. Or is this a new thing for you?”

“It’s not…” Fuck, why is he even explaining this? “He’s just...admiring. We...stopped. At least when we’re switched like this. It seemed rude.”

Zichen knows he’s blushing—he can feel the heat under his skin—and a distant part of his mind wonders what that looks like on green skin.

Ensign Xue looks surprised for a split second before he rolls his eyes. “Wow, so thoughtful, especially since I _know_ you’re a fucking liar.”

Zichen is irritated. He is trying to be nice. “Fuck off. We stopped after that first time, okay?” Well, after the holodeck, which he doesn’t mention. “I’m trying to be nice. We’re trying to be nice.”

For some reason, that seems to piss Ensign Xue off. His eyes narrow, and he looks practically murderous. He takes a step toward Zichen, fingers curling into fists.

“Don’t be nice on my account,” he growls. “You never have been before.”

The anger that had started to build in Zichen fizzles abruptly. In that voice, his own voice, Zichen can hear the...hurt? Why would Ensign Xue be hurt that Zichen isn’t nice to him? It’s unnerving, and just like that, he’s back to being mad about it.

“Yeah, you’re right. Why should I bother?” Zichen fires back and leaves, grabbing a cryosensor so he can run temperature checks in the quiet of a Jefferies tube.

He’s still fuming when he is summoned to the transporter room. How dare Ensign Xue act like Zichen is the one at fault? And furthermore...at fault for what? They aren’t friends. They’re barely acquaintances. What did he expect?

“This better fucking work,” Ensign Xue mutters, and Zichen refuses to acknowledge that he agrees.

It doesn’t.

Within a day, Ensign Xue and Xingchen switch while Xingchen is performing an appendectomy. It’s only luck that he’s turning off the laser before he collapses on the ground.

Xingchen, who is rarely shaken by anything, is quiet through dinner, the rich avocado green of his new skin ashen and wan. He tucks himself under Zichen’s arm and picks at his food. “I think I fought it, Zichen. It hurt. More than before. I was just...when I woke up, I was so afraid for Ensign Aeryn. I could have killed her.”

Zichen smooths his hand over the black hair that belongs to this body. It’s long and wavy on top, short and downy on the sides and back, and Zichen curls the long, soft pieces around his fingers. He glances up and sees Xue-in-Xingchen a few tables away, also poking the food on his plate with an uninterested fork.

“Hey, Ensign,” he says, “Ensign Xue.”

Ensign Xue continues to push his fork in a circle either not hearing Zichen or ignoring him. Whatever. He’s not going to beg. If the man wants to eat alone, that’s his business.

“Try again,” Xingchen says, and Zichen sighs.

“Xue Yang, come join us,” Zichen says again, no louder than the first time, but Ensign Xue’s fork stops moving. “Buy you a drink?” Zichen offers, and the corner of Ensign Xue’s mouth twitches.

“You just want to look at your pretty Bajoran,” he gripes, but he picks up his plate and shifts tables, plunking down across from them.

Xingchen sits up. “You think I’m pretty? Thank you, that’s so sweet,” he says, all sincerity, and Ensign Xue’s lips twitch again, this time in the definite start of a smile.

Xingchen is magic like that, Zichen thinks, always able to put people at ease. It doesn’t usually work that way for him. People _like_ Xingchen, they respect Zichen. People are comfortable around Xingchen, they’re wary around Zichen.

“Did this switch hurt you too?” Xingchen asks, and Ensign Xue frowns before he nods once, as if he doesn’t want to admit the injury. As if hiding it will make it not have happened.

“I’m sorry,” Xingchen says.

“Nah, it wasn’t you,” Ensign Xue shrugs. “They’ve gotten worse every time.”

Zichen is surprised. He hadn’t noticed that. “Are you sure?” he asks, and Ensign Xue rolls his eyes.

“Yeah, I’m pretty familiar with escalating pain. Security, remember? And...Orion.”

He doesn’t explain what that means and Zichen doesn’t ask, but he glances at the four-fingered hand resting on the table. Outside of the crime syndicate, which isn’t technically sanctioned by the Orion government, surprisingly little is known about Orion culture, society, and biology—all mysteries they prefer to maintain, probably so they continue to be viewed as Federation neutral. Now that Zichen thinks about it, it’s unusual for any Orion to join Starfleet, much less a male Orion. They tend to be secretive and Starfleet doesn’t like secrets.

“Why did you join Starfleet?” he interrupts whatever Xingchen had started to ask Ensign Xue.

Ensign Xue grimaces. “Nosy. Why did _you_ join?”

Zichen shakes his head, almost laughing. Yup, secretive.

“I always wanted to. I can’t remember a time when I didn’t want to fly,” he says, and even though he’s never reticent about sharing this bit of himself, there’s something about the way Xue tilts his head and tilts his mouth that makes Zichen look away.

“I thought I joined to be a better doctor and scientist, but now I think...maybe I just wanted the freedom,” Xingchen muses. “I wanted to see something more than Bajor, in case…”

He doesn’t finish, but Zichen knows what he means. Bajor is still a world in recovery after being occupied by the Cardassians for decades, and Xingchen had been born before their withdrawal. Freedom isn’t a given. Zichen squeezes Xingchen’s hand.

“So noble. Should’ve guessed. I just wanted to learn to fight, and the Klingons weren’t taking apprentices,” Ensign Xue mumbles.

Zichen laughs, and Ensign Xue looks startled. Something about his face softens, easier to recognize on Xingchen’s familiar features, and he adds, “Plus, I wanted to get away from Orion. As far away as possible.”

Something twinges in Zichen. He’s seen Ensign Xue’s body now, more than once, and although he’s never going to ask, he’s seen the marks on it, marks he certainly didn’t get training to be StarFleet security.

Xingchen lifts his glass. “To seeing the universe,” he says, and even Zichen can toast to that.

★ ★ ★

The realignment team switches them back in the morning—the Titan hadn’t gotten far from Yecal VI—and before anything else disastrous can happen, before they’re attacked by tribbles, before they're turned into a million-gallon vat of custard, before a giant space whale pops out of a black hole to swallow them up, Xingchen hauls Zichen back to their room.

“Clothes. Off. Now,” he demands, and Zichen laughs, more than happy to do as he’s told. Xingchen is not often rough and domineering, and Zichen loves it when he is.

“Tired of the swapping, huh?” Zichen asks as Xingchen tightens his hand in Zichen’s hair and kisses him, biting and bruising, before pushing Zichen back onto the bed.

“Tired of not seeing you naked. Tired of not watching the heat of your skin change colors in my eyes. Tired of not hearing you beg,” he answers, and Zichen groans.

“You’re going to be the death of me, Xiao Xingchen,” he gasps as Xingchen wraps a slippery hand around Zichen’s cock before sinking down onto him, impaling himself on Zichen and rocking his hips forward.

Zichen lets Xingchen take what he wants for a little while, stroking him smoothly as the long line of his body undulates slowly on top of Zichen. He loves this vantage, watching the way pleasure reshapes the curved bow of Xingchen’s mouth, and he matches the measured pulse of Xingchen's breathing.

“Harder now,” Xingchen tells him, sliding his thumb down Zichen’s throat, pressing into the cartilage. “Fuck me harder,” and like the words are a magical spell, Zichen is all out of patience and restraint.

In one swift move, he rolls Xingchen onto his back.

“Love you,” Zichen tells him before plunging into him hard enough that Xingchen gasps, arching his back and reaching out to seize Zichen’s arms.

“Too,” Xingchen concurs in a long, satisfied exhale, urging Zichen with hands on his chest, his face, his neck—anywhere he can reach. “Love you too.”

Somehow, though, no matter what they do, no matter how they do it, Zichen feels like he’s the one who’s begging, wanting Xingchen more than should be humanly possible, his words all garbled, muffled in the curve of Xingchen’s neck. He’s always at risk of losing himself in Xingchen, but it’s always a risk worth taking.

When it hits, his climax feels like a tangible thing, a core of golden light building inside him only to shatter into tiny particles, the atoms of his humanity fading into nothing.

It is some time before Zichen feels put back together enough to attempt speaking or movement.

“Hey,” he says, congratulating himself on how articulate he is, all things considered.

Xingchen wraps a lock of Zichen’s hair around his finger. “Hello.”

Zichen slides to the side, cuddling Xingchen to him, breathing in the honey and lemon of his soap and the something underneath that’s just him.

“You’re going to be late for sparring,” Xingchen informs him with a satiated grin, and Zichen sighs.

Part of him would rather just skip it and lay here a little longer, but he knows he can’t. After he’d apologized to Lieutenant Lan for kicking him and explained what had happened, Lan had looked intrigued—as intrigued as possible for a Vulcan, at least—and asked Zichen to try again sometime in his own body.

Although Wuxian, Zichen’s usual sparring partner, is a skilled fighter, he and Lan are surprisingly well matched, and Lan is trained in a variety of techniques, even Earth-style sword fighting. It is, for Zichen, the best combat exercise he’s had since he left home. He doesn’t really want to jeopardize this tenuous friendship.

“I’ll come with you. My shift doesn’t start for another hour, and I’d like to see you spar, if that’s okay?” Xingchen adds, and Zichen kisses the ridges on his nose. “Maybe I’ll see if Wuxian is free.”

Meddling, Zichen thinks, laughing to himself. Always meddling.

They arrive one minute early to the training room, where Lan is frowning as though Zichen is ten minutes late. Wuxian bounds through the door behind them, grinning at Xingchen, and Zichen sees Lan’s attention shift. It’s only the slightest change, but on a Vulcan, it might as well be a full sensor array realignment, a sunflower turning to follow the sun. Zichen smiles to himself. That _might_ make the fight easier, he thinks, but he’ll have to be more careful.

“Weapons?” he asks, and Lan nods, tossing Zichen a lightweight double-edged sword, barely waiting until it’s in Zichen’s hand before attacking.

It’s funny, watching the normally impassive Lan change when he’s fighting. He takes on a fiercely-determined intensity that makes him both harder and easier to fight. Easier, because he doesn’t disguise his intent. Harder, because he’s so good, he almost doesn’t need to.

Lan is breathtakingly fast, his long legs and reach forcing Zichen back into defense. But Zichen likes defense. He’s a patient fighter, matching Lan strike for strike, poking at him when there’s an opening, occasionally parrying with more strength and speed than Lan expects. It’s his unpredictability that Zichen suspects Lan enjoys about their fights, and he thinks it says something about the man that he finds unpredictability interesting.

Zichen lets Lan get closer on every slash before he steps in, closing the gap in his guard and lifting the other man’s sword up high. He intends to see if he can set Lan off balance enough to get the win, but Lan spins to the side, blocking Zichen’s downward hack with remarkable strength, and sweeping the sword sideways. The tip of the sword circles back more quickly than Zichen anticipated, and he only barely has enough time to block it up and away from his throat. He’s irritated with himself for giving up such an obvious opening. Zichen takes a step back to regroup, but before he can formulate a new attack, Lan’s communicator beeps, the two tones they both know means “urgent.”

Dropping his sword arm, Lan taps the communicator. “Yes?”

“Lieutenant Lan, please report to the bridge immediately,” the voice says, and Lan frowns.

“Right away,” he answers, and nods to Zichen.

“Lieutenant Song, thank you for the match. My apologies. We will have to continue later.”

“Yes sir,” Zichen answers automatically, but Lan is already replacing his sword on the rack and walking out of the door.

“Well fuck.” Ensign Xue’s voice breaks the silence, startling Zichen. He hadn’t seen the man come in. “He’s my training instructor. Think he’ll be back in the next ten minutes?”

“You can fight Zichen,” Xingchen pipes up, and Zichen turns to glare at him and Wuxian, who have identical innocent-not-innocent looks on their faces.

“Ha,” Ensign Xue snorts, more disdainfully than is strictly warranted. “A human? No thanks.”

Good, Zichen thinks.

“Afraid?” Zichen asks, raising an eyebrow.

 _What is wrong with you_ , he wonders, as Ensign Xue’s nostrils flare and he takes an angry step toward Zichen. Why, why, _why_ did he open his mouth? Why is he egging him on? He doesn’t even want to spar with the Orion.

“Fuck you,” Ensign Xue snarls. “Afraid of what?”

“Losing?” Zichen asks casually, and with a grunt, Xue throws himself at Zichen, the power of his punch arcing up from his shoulder, and Zichen just has time to block it with his forearm, aiming his own fist at Xue’s stomach.

Xue twists sideways, hitting Zichen with his hip and pushing him back, following him with quick repeating strikes at his head that Zichen blocks, only barely avoiding the knee to his groin. It takes him a second to find his bearings in the fight. He’s stunned by how strong and quick Ensign Xue is, a blur of kicking feet and hitting hands. Every fight has a personality, Zichen thinks, and this one is a street brawl, not an elegant, mediated spar.

Fine.

He can do that.

Ducking below Xue’s swinging arm, he catches him around the waist and flings him onto the mat, but Xue just rolls backward and jumps up, barely giving Zichen a second to collect himself. With a start, he realizes that Xue has the black knife in his hand.

Zichen wonders where it came from. It’s bigger than he thought, almost the length of his forearm.

Xue aims the knife at Zichen’s side with a hard thrust and Zichen dances back as Xue side steps and slashes the knife up at his face. Zichen catches his arm on the upswing and lands an elbow strike on Xue’s ribs. Xue’s breath gasps from his lungs and he staggers back, eyes filling with fury. Fuck. _It’s an Orion thing_ pops into Zichen’s head and he wonders if Xue is better or worse when he’s enraged.

Better. Of course.

Zichen doesn’t even think, just lets his body take over, catching Xue’s swiftly moving hands when he can and avoiding the knife when he can’t. He lands a few hits—knee to the hip, spinning shove, a punch that was aimed at Xue’s face but hits his chest just below his collarbone—but he’s getting tired, and he knows he won’t last much longer.

With a grunt, Xue jabs the knife at Zichen again, and Zichen finally gets a firm grip on his wrists, sweeps his leg behind Xue and drives him into the mat. Zichen pins Xue’s hands above his head and uses his leg to bear down on Xue’s hips. This is his only real advantage, his size and weight, and he uses them as relentlessly as he can, hitting Xue’s hands against the ground until he lets go and the knife spins away.

“Do you yield?” he asks, looking into blazing black eyes, noticing for the first time that the irises are flecked with shades of green too, just around the pupil.

Xue struggles for a second, panting for air, and Zichen grins at him. “Come on, I won. But you’re…” He pauses. Does he want to say this? “You’re good. _Really_ good.”

Xue’s face goes slack for a second before he hisses, “Get the fuck off me.”

Zichen lets him up. It’s not exactly a yield, but he suspects it’s the best he’s going to get. As soon as he’s free, Ensign Xue grabs his knife and storms out. Zichen sighs. He has such a way with people, he thinks a little ruefully. For once, he’s trying to be nice and Ensign Xue acts like Zichen is the one who attacked _him_ with a knife.

“Wow, damn, I had no idea you could fight like that,” Wuxian calls out.

Zichen shrugs, dismissing the compliment. “It’s nothing. I was an active kid. After I broke the second couch jumping onto it from the roof, my parents found a ‘better outlet’ for my energy.”

“He’s kind of cute, don’t you think?” Xingchen says, staring at the door.

“Thanks,” Zichen says, kissing Xingchen’s forehead.

Xingchen grins. “Of course I think _you’re_ cute. I meant Xue Yang. He’s cute.”

Wuxian and Zichen exchange a look.

“Love, I am personally fortunate that you have questionable taste in men, but...no. Not cute. No more than a carnivorous rastipod is cute.”

“Hm,” Xingchen muses, undeterred. “Maybe cute isn’t the right word.”

No, Zichen thinks, remembering the way the wild rage transformed Ensign Xue’s face. Cute is not the right word at all.

★ ★ ★

Peace lasts for two more days. There are cautious whispers from their realignment team, the odds of them finally stabilizing increasing with every passing hour.

Zichen is in the middle of flushing the electroplasma conduits when he feels the now-recognizable ache in his fingers and toes a heartbeat before the twisting yank overtakes him. It’s only enough time to brace himself for the pain. He lays, panting on the ground of sickbay for a second before he has the strength to call back to engineering.

Ledrah informs him that luckily, Ensign Xue didn’t pass out and was able call her over, or the plasma injectors could have overflowed and caused a catastrophic system failure.

As an added bonus, before Zichen can even reaccustom himself to seeing the world through colorful blobs of the VISOR, the aliens, which have been oh-so creatively dubbed Species 8675 make a third appearance, chasing the Titan for a solid 1.89 light years at warp 7 before abandoning the fight.

They aren’t called to the transporter room again. They’re called to the captain’s ready room.

It’s the worst thing Zichen can imagine. Since he joined Starfleet, Captain Riker is the only commanding officer who’s never asked Zichen to explain himself, the only captain who’s looked at him and seen only Zichen. He hates that _this_ is going to be how his captain sees him now: as an abnormality to be dealt with.

“Here’s the problem,” Captain Riker tells them. “We don’t know what’s happening. And we can’t keep flitting around from planet to planet trying to fix it. Not only do we have a continuing mission, this...body swapping...is dangerous. Especially since it might be what’s attracting our new friends.”

Zichen-in-Xingchen and Xingchen-in-Xue exchange a startled glance. That hadn’t even occurred to Zichen.

“For now, we’re going to leave you as you are. I know, it’s not what you wanted to hear,” Captain Riker says, holding up a hand when Xue-in-Zichen opens his mouth to object. “And I know you aren’t going to want to hear this either. Effective immediately, you are all relieved of duty for the near future. We’re heading back to Kryal IV, and we’re working on a new plan. But it’ll take days to get there and days to figure out a workable strategy. You...” He looks remorseful, not a look Zichen likes seeing on the captain of his ship. “You may need to consider the possibility that there is no quick solution.”

Zichen staggers back to his room and curls up in a ball on his bed. He tries not to cry, but tears slide down his cheeks when he remembers the first time he’d looked through his telescope and watched a starship leave the San Francisco Fleet Yards orbiting Earth. _Someday_ , he’d thought, _that’s going to be me_.

He had been six years old.

He’d been fourteen the first time he left Earth orbit, and even though it was nothing spectacular, something people did every day for work and pleasure, it had felt like magic to him. How could anyone not be captivated by the wide mystery of space? How could he ever be happy with anything else?

“Zichen?” Xingchen sounds hesitant, and Zichen looks up at him, the rainbow of light that shapes itself around his face revealing his worried expression. “Do you want to talk about it?”

Zichen shakes his head and lifts his arm, making a space for Xingchen in front of him. Xingchen snuggles in, wrapping his arms and legs around Zichen. The Orion body isn’t the same as _Xingchen_ , but it’s still comforting. Zichen tucks his head under Xingchen’s chin and, even though he knows the abstinence was his idea, he is suddenly ravenous to be touched, to be loved. He gently kisses the tiny peek of collarbone he can see and pulls Xingchen tighter to him. Xingchen exhales and tilts his head back as Zichen knew he would. He hooks one leg around Xingchen’s thigh and rubs against him, delighting in the sharp lightning that arcs through him. He ignores the door alert the first time it beeps and the second, but finally, Xingchen sighs and pulls away.

“I don’t think they’re going to leave,” he tells Zichen, and then tells the uninvited interloper, the cruel invader, the disagreeable intruder, “Come in.”

It’s Xue-in-Zichen. Zichen almost throws a vase at him, but Ensign Xue holds up a bottle.

“Captain has good taste. Wanna get drunk?”

It’s whiskey, beautiful, glorious whiskey, and Zichen, who rarely drinks, thinks it’s the best idea Ensign Xue has ever had.

★ ★ ★

“And then he said ‘why would Junior Lieutenant Wei be interested in encountering my leg strength?’” Xue says, and Zichen howls with laughter, falling backward to stare at the ceiling. “Seriously, can you fucking believe it? Vulcans are supposed to be so smart, but he has no idea.”

“Neither of them does.” Xingchen hiccups and hands the bottle back to Xue. “Last week Wuxian wondered if Lieutenant Lan would like one of the crystallia plants since, and I quote, ‘he comes down here to smell them so often.’”

“Damn, they’re such idiots,” Zichen laughs. “Can’t even tell that they like each other.”

“Yes, indeed, what kind of fool can’t tell when someone likes him?” Xingchen says with what is almost a giggle.

“Shut up, Bajoran,” Xue mutters, and Zichen is confused. Do they have a secret? Who likes someone? Does Xue like someone? He wants to know. Why doesn’t he get to know?

“I am currently Orion,” Xingchen informs him primly, holding out an arm. “See? Look at my pretty green skin.”

“Don’t rub it in,” Xue grouses.

“I have not been _allowed_ to rub _anything_ in a _while_ ,” Xingchen sighs morosely, and this time Zichen does know what he’s talking about.

“Shut up, Bajoran,” he echoes, blushing. It’s not even _true_.

Xue rolls Zichen’s eyes in Zichen’s face. It looks inexplicably funny, and Zichen idly wonders if Bajoran physiology gets drunker faster. He certainly feels drunker than he can remember ever being. Of course, his memory is a bit dodgy at the moment. Probably because he’s drunk. _Cause and effect_ , he tells himself, and it feels very meaningful, although he can’t quite nail down why.

“Are you drunk?” he asks Xingchen, and Xingchen shakes his head.

“This body resists my efforts,” he says, gesturing at himself with a dramatic flourish.

Xue laughs. “I’m not drunk either, but fuck, I don’t know why you humans aren’t drinking all the time. Everything tastes so much better in this body.”

Xingchen’s eyes widen. “I know! The first...well...the second thing I did in Zichen’s body was try ice cream. Have you had the ice cream? No? You need to try ice cream. It’s good if you’ve got a Bajoran tongue. It’s sublime if you’re human.”

He stands—pretty unsteadily for someone who claims they aren’t drunk, Zichen thinks—and weaves his way to the replicator, returning with a bowl of double chocolate chunk ice cream. Instead of handing it to Xue, he lifts a spoonful.

“Eat,” he commands.

Xue licks his lips and obeys, opening his mouth. Xingchen slides the spoon in, and Xue’s lips close around it. He shuts his eyes as he considers, and Zichen shuts his so he doesn’t have to consider...anything at all.

“Fuck. fuck, _that’s_ what ice cream tastes like? More. I want more,” he demands, and Xingchen laughs, lifting the spoon again.

It’s the laugh that does it. Even in Xue’s voice, Zichen knows that laugh. And because he hears Xue’s words in his own voice, he knows what Xue is asking for. What Xue is hoping for. He’s heard himself sound that way often enough. Is that the secret? Not much of a secret. Everyone loves Xingchen.

But.

Xue looks at Zichen and bites his lip when he swallows the ice cream.

An impossible hypothesis pops into Zichen’s mind, and he is a scientist. A hypothesis requires _testing_.

“No,” Zichen says, meeting Xue’s eyes and kneeling to kiss Xingchen’s ear. “I want more.”

Xue doesn’t look away, and Xingchen only pauses for a second before turning the spoon to Zichen.

“Here,” he says softly.

Zichen accepts, licking the ice cream off the spoon. Still watching Xue. Still waiting for a reaction. What he gets is slightly widened eyes and a hitch in his breath. If it was anyone else’s face, Zichen wouldn’t know what it meant. Since it’s his own face, he is completely aware. Dumbfounded, but aware. He hadn’t realized. He’s an idiot who hadn’t realized. He kisses Xingchen’s mouth lightly, without demand, but with a definite question. Xingchen huffs at him, a _yes, of course_ huff.

Without being asked, Xingchen offers a spoonful of ice cream to Xue, and Xue takes it.

“More?” Xue asks when he finishes swallowing, an unusually tentative note in his voice.

“More,” Zichen agrees, and leans forward to kiss him, to kiss Xue-in-Zichen with Xingchen’s lips.

It is dazzling in every way, from the taste of the ice cream, to the feel of his lips, to the finally-surrendered tension, and Zichen presses in, cupping his hand around the back of Xue’s neck. Xue makes a broken sound of surprise before opening his mouth, whimpering when Zichen tugs on his lower lip. There’s a part of him that’s fascinated by the novelty of kissing himself—how often do you get to do _that_ —but he isn’t deluded. It isn’t this body he wants. It’s Xue. And Xingchen. He wants _more_.

Xue touches a hand to Zichen’s face as if he’s afraid he’s making a mistake, and Zichen turns his head, nibbling the tip of Xue’s finger, relishing the way Xue’s eyes blink, rapid and startled.

“This isn’t...this isn’t a joke?” Xue asks. “Or some weird clone fucking thing?”

“Not a joke,” Xingchen answers, closer than he had been, just over Zichen’s shoulder. “Might be a clone fucking thing. Do you mind if it is?”

Zichen trails a path around Xue’s ear with his tongue before biting his earlobe, and Xue shudders.

“Not really, no,” he answers shakily before Xingchen kisses him too, pressing against Zichen’s back.

Xue is already sitting on the ground, so it takes practically no effort at all for Zichen to push him backward, kneel over him and kiss him harder, take more from his mouth and tongue. It’s amazing, he thinks, how quickly he can dismiss the details of the body in favor of the consciousness. Logically, he knows this is his own body he’s kissing, and maybe it’s because the VISOR blends everyone’s features together, reducing them to swirls of heat, but it doesn’t seem as strange as he thought it would. Oddly, he’s only thinking about it being Xue, and it _feels_ just right.

Xue is just wearing a t-shirt, having shucked the jacket half a bottle of whiskey ago, and Zichen pulls it off impatiently. He touches his lips to Xue’s neck, breathing in his scent, not his own scent, but the spice that reminds Zichen of wood fires and black tea leaves. When he cautiously bites one nipple. Xue surges against him with a moan, a sound that ricochets through Zichen and scrambles his brain. The second time, Zichen bites him harder, hard enough that Xue cries out and digs his hands into Zichen’s hair.

“No?” Zichen asks, teasing his fingers down Xue’s stomach and watching the muscles clench. He reaches the waistband of Xue’s pants and taps his finger thoughtfully against the clasp.

“Fuck, fuck, Zichen, you asshole, please,” Xue complains, writhing and clutching Zichen’s shoulders. “You know I want you, just...please…”

Wanting, wanting, always wanting, Zichen thinks. But no, that’s his Orion body that wants and wants. Does he really want Zichen in this body too? In any body? It is, frankly, too confusing for Zichen’s buzzed brain to keep track of. Besides, he is increasingly aware of Xingchen’s demanding hands, which are turning what little mental acuity he has to jelly. He doesn’t have much time before Xingchen does something to completely transform him into mush.

With a snort of annoyance at complications like buttons and zippers, Zichen finally fumbles open Xue’s pants, and Xue obligingly lifts his hips so Zichen can yank them down. Without preamble—he _really_ doesn’t have time for preamble; he feels like he’s already months late—he sucks Xue’s cock into his mouth, tightening his lips and tongue until Xue cries out. He wants to punish Xue for every annoying, rude thing he’s ever said instead of the truth, and he thinks he might succeed, if the frantic way Xue is bucking into Zichen’s mouth is any indication.

Xingchen tugs on Zichen’s hips and he shifts, wanting whatever Xingchen wants, everything Xingchen wants. He feels wet fingers on his ass, tracing a path down his cleft to the ring of muscle, just as sensitive in this body as his own. Zichen’s eyes close as Xingchen pushes into him ruthlessly, exactly what he wants, exactly right. His hand finds the rhythm of Zichen’s mouth on Xue’s cock and they move together, the three of them, even in unfamiliar bodies, like they’ve always done this.

Zichen is on the brink of dissolving when Xingchen stops and kisses his back at the base of his spine. “My love,” he says tenderly, as he slides his cock into Zichen.

Zichen’s knees shake. His entire body shakes. The pebbled texture of the Orion body inside him is extraordinary, not the excruciating rapture of how it usually feels with Xingchen, more like the inevitability of water and stone. Zichen fights to keep his wits, at least long enough so he can enjoy this. As it is, he pitches forward and his teeth scrape against Xue. Xue moans piteously, high-pitched and helpless, and it makes Zichen want something—to own him, to hurt him again, but also to brush his hair off his forehead and kiss his temple. It is a baffling contradiction.

“Zichen...Zichen... _Zichen_ ,” Xue moans, “I _hate_ you.”

He sounds so earnest, Zichen’s laughter rumbles through him, vibrating around Xue. Xue gasps, the sweetest sound, before climaxing hot and bitter in Zichen’s mouth. He swallows reflexively over and over, more than a little pleased at the way Xue keeps quivering underneath him even after his body goes slack.

Xingchen’s hand closes around Zichen’s cock—technically Xingchen’s cock—and he presses his fingers against the sixth and seventh ridges, the ones furthest from the tip. Zichen buckles, every muscle emptied of strength at once, and he tips forward onto the warm comfort of the person beneath him—his body, but Xue’s embrace. He shouts, cries, _screams_ Xingchen’s name, and he knows Xingchen is coming too even as Zichen is being sundered, falling into a glorious sea of pleasure as the world fades away, lost in the thundering white waves.

Zichen lays still between two bodies, one under him, one behind him. Warm breath tickles the back of his neck, and lips press against his skin. Fingers run through his hair and over his arm while he thinks about the transitive property and how absurdly obvious it is. He thinks about coherence, resonance, and other ties that knit and bind. He thinks about the great relief of equilibrium.

“Xingchen,” he murmurs, opening his eyes, and the fingers abruptly stop.

The body under him tenses, moving before Zichen can tighten his arm around the waist he’s holding.

“I gotta go,” Xue says, untangling from Zichen.

“You don’t,” Xingchen points out from where he is laying behind Zichen.

Xue’s laugh is almost shrill. “Yeah I do. What, I’m just going to stay here and hang out in _your_ room, _your_ bed, your little _life_?”

“You could.”

Xue pauses, and Zichen tries to identify the expression on his face, the VISOR failing him at what seems like a critical moment. Maybe it’s longing, maybe Zichen only assumes it is.

“Nah, I’m good,” Xue finally bites off the words. “Thanks for the fuck.”

The last snide comment seems to be directed at Zichen, and he blinks in surprise. Xingchen’s tone sharpens. “Don’t blame him. This is your choice.”

Zichen is surprised at how unfeeling Xingchen sounds, but when he looks, Xingchen seems sad rather than cruel. It’s so frustrating not to know for sure, and he feels entirely left out of this conversation.

“Yep. My choice. _Mine_ ,” Xue snaps, and before Zichen can understand why he’s so angry again, why he always defaults to unnecessary anger, he’s gone.

“What the hell?” Zichen asks, staring at the closed door.

“I don’t know, love.” Xingchen sounds tired. “I don’t know, and this body is exhausting. So hard to keep calm. Will you come to bed? I need...I think I need to lay down.”

Zichen curves around Xingchen and kisses him, rather than try to figure out what Xue is pissed about. A tiny voice tells him he knows exactly why Xue left, that it might not be anger, but another part of him is annoyed that Xue isn’t even trying. Relationships take communication from both sides, he thinks irritably, and yet another part of him is aghast. _Relationship? What the fuck, Zichen?_

His arms and legs feel heavy and dense, and before the oxytocin crash and whiskey can send him to sleep, Zichen wonders what he’ll dream about.

“Do you dream of other places when you’re in another body?” Zichen mumbles when Xingchen’s breathing seems settled and calm.

“No,” Xingchen says, turning to burrow his face into Zichen’s neck. “Why? Do you?”

“Not really. Nothing specific,” Zichen lies, hating himself. He shouldn’t have asked. He already knew the answer.

It feels like the icing on a shit cake that the ship goes to red alert, preventing the welcoming silence of sleep, and Zichen and Xingchen can do nothing but stay in their room and wait for orders.

★ ★ ★

Apparently, Wuxian tells them in Eleven Aft the next day, there was an incursion.

“I was in the training room...uh...sparring with...uh...Lieutenant Lan,” he says, with a guilty flush, and it is hard for Zichen not to roll his eyes. “And this alien materialized in front of us. Absolutely terrifying. Black horns, red skin that looked like cracked stone, and fangs. Actual fangs. Like some sort of demon out of myth. Lan Zhan tried to fight it, but it was just some kind of hologram. A _hologram_ , Song. It didn’t do anything, just scanned the room with this little wand thing, made a face, a _someone must die_ face, and disappeared.”

It _is_ a horrifying prospect, horrifying enough that Zichen doesn’t even tease Wuxian about calling Lieutenant Lan by his given name. How could an alien manifest a hologram inside the shields during red alert?

“Are they looking for something?” Zichen asks, and Wuxian shrugs.

“No one knows. But I’m pretty sure I’m going to sleep like a baby tonight—fitful and crying.”

Zichen laughs, but the smile dies when Xue walks in, sees them, and walks out.

“Weirder than usual,” Wuxian comments, and Xingchen frowns.

“I don’t think I’m going to let him get away with that,” he remarks offhand, like he’s talking about the weather on Bajor, but he climbs out of the booth and strides purposefully toward the door, hands clenched at his sides.

“Uh...that seems like a problem,” Wuxian says, and Zichen agrees.

Scrambling to his feet, he follows Xingchen-in-Xue, who is following Xue-in-Zichen, down the hall. They’re a farcical line of ducks, and Zichen feels foolish chasing after them.

“Xingchen, wait,” he calls, and then he feels it.

No. No, not now, not right now.

_sharp teeth tearing_

_folding_

_unmaking and remaking_

Fuck, Xue is right, it _is_ getting worse, but he knows without looking that he is himself, human Song Zichen. That’s the upside. The downside is that he’s on the ground, lights are flashing, alarms are sounding, and Wuxian’s alien demon is striding toward him.

No. Not him. The alien is looking at Xue, passed out between them.

“Stop!” he shouts even though it’s stupid stupid _stupid_ to draw the big scary monster’s attention, and even stupider to get up and run toward it, putting himself between the approaching intruder and Xue’s limp body. He holds up a hand, drops back into a fighting stance, and yells again, knowing it’s pointless.

But the alien stops. He tilts his head in a way that suggests curiosity. He waves the little wand thing Wuxian described and reaches out like he is going to touch Zichen with one clawed hand. But before anything happens, he grimaces and disappears.

Xue’s eyes are wide, and Zichen doesn’t think he’s processing at a hundred percent yet.

“Is he okay?” Xingchen-in-Xingchen asks from behind him.

“I’m fine. Fuck, that one hurt.” Xue tries to pull his feet under him to stand. He manages, but wobbles precariously.

Without thinking or waiting to see if Xue topples into the wall, Zichen scoops him up and starts walking.

“The fuck do you think you’re doing, human?” Xue snarls, wiggling to get away, but Zichen doesn’t let him.

“Taking you to sickbay, pirate. Stop fighting me.”

Maybe it’s the familiarity of mocking, maybe it’s the fruitlessness of struggling, but Xue stops moving, folding his arms and looking aggrieved.

“I hate you,” he grouses.

“No, you don’t,” Zichen says, crooking his mouth in a tired smile. “You want me, remember?”

Xue flushes, a soft lavender under his skin, and Zichen kisses him on the temple.

Dammit. Xingchen was right. He _is_ cute.

Dr. Wen pronounces Xue healthy, but before they can leave, she adds, “I’m concerned about the toll this is taking on all three of you. We’re only a few hours from Kryal IV, so I’m keeping you here for the night. Do not stress yourselves before then.”

She looks at Zichen and Xingchen and points a finger at Xingchen. “I mean it. No stress of any kind,” she emphasizes.

Xingchen has the nerve to look affronted by her reprimand.

Hours later, Zichen wakes to Xingchen shaking his shoulder. Frankly, he’s surprised it took so long.

“Come on,” he says, finding Zichen’s hand, and even though Zichen has no idea where they’re going, even though he’s being led by a blind man through the dark, it doesn’t really matter. He follows Xingchen.

They don’t go far.

“Move over,” Xingchen hisses, climbing into Yang’s bed.

“No!” Yang hisses back, but it’s no use. Zichen could have told him it wouldn’t be any use.

With a smile, Zichen follows suit, sliding under the blanket, wrapping an arm around Yang before he can scoot away. Xingchen touches his forehead to Yang’s. Zichen fits himself to Yang’s shape, hip to hip, knee to knee, shoulder to shoulder. Xingchen drapes an arm over both him and Zichen. Zichen inhales Yang’s spice and cedar mixed with Xingchen’s honey and lemon, filling his senses with safety and comfort and peace.

“You’re both lunatics. What are you doing?” Yang demands, but he doesn’t sound angry for once. He sounds genuinely bewildered.

“We want you too, Yang,” Xingchen says unceremoniously. He yawns. “Now go to sleep.”

Yang tenses, but Xingchen’s eyes are already closed.

Rather than adding anything to the truth already stated, Zichen just kisses the side of Yang’s neck and snuggles him closer. Xingchen’s arm around them tightens, and it takes almost no effort to slip into a dark grey sleep.

★ ★ ★

Dr. Wen doesn’t comment when she finds them the next morning, only hands Xingchen his VISOR and tells them that the realignment team is meeting in an hour.

“Hopefully the last meeting,” she says, a sentiment Zichen suspects they all share.

There are no smiles when they enter the conference room, and only nods of acknowledgement from Ledrah, Lieutenant Commander Palmer, and Counselor Troi. Zichen notices they’ve been upgraded from Senior Security Officer Luo to Chief Tactical Officer Jaxa, and Captain Riker is now sitting at the head of the table.

“Gentlemen, thank you for joining us,” Captain Riker says when they sit.

Zichen can’t help relaxing a little; the calm, friendly voice is one of the captain’s best qualities, and Zichen has always had faith in Captain Riker’s leadership. He was Zichen’s first childhood hero when he was an officer on the Enterprise—Zichen even had a “Join Starfleet” poster of him hanging in his room—and Zichen has never wanted to serve on any other ship. But his stomach clenches when it occurs to him that if whatever this new plan is doesn’t work, it may be the end of his career on the Titan, maybe in Starfleet.

And then he remembers the increasing pain of shifting and an exciting new flood of anxiety overwhelms him. Starfleet might be the least of their worries.

“As you know, we’ve tried a number of options,” Lieutenant Commander Palmer says. “The only thing we haven’t tried is replicating the exact circumstances of The Incident.”

Zichen can actually hear the capital letters in her words.

“There is a solar flare happening today in eight hours. It won’t be the same intensity, but hopefully that won’t matter,” Dr. Golwat adds.

 _Hopefully_. Very inspiring, Zichen thinks.

“So, the plan is to transport you to the surface with the away team, check your transporter data once you’re there, wait for the solar flare, and transport you back. Simple and, we hope, effective,” Captain Riker explains.

Zichen would have more confidence in the simple plan if it wasn’t the third week of simple plans he’s heard.

“Because of the added complication of Species 8675, we don’t want you on the surface any longer than necessary. Therefore, be ready to transport fifteen minutes before the scheduled solar flare. We are taking a full security detail just in case, but we aren’t sure how effective we’ll be against them.” That cheerful bit of news comes from Commander Jaxa.

“This is a lot to take, I know.” Captain Riker sounds sympathetic. “Do you have questions?”

“Yeah, what if this doesn’t f...work?” Yang asks. “I mean, that’s the only real question, isn’t it?”

The room is silent for longer than is comfortable.

Dr. Wen sighs. “While it doesn’t seem that the cycles are getting faster or causing physical damage, it is my understanding that they are painful and causing mental stress. We,” Dr. Wen glances at Counselor Troi, “can teach you pain management and…” she hesitates. “We can try sedatives if it becomes necessary.”

“Sounds great,” Yang chirps. “Life as an Alvinian melon. All I’ve ever wanted.”

No one reprimands him for being insolent, and that more than anything makes Zichen realize that none of them actually think this will work. This is a last ditch effort, not a real solution.

He’s going to die, he thinks, because he is certainly not going to spend his life in tranquilized catatonia.

For some reason, it’s comforting not to have any hope. No hope means no expectations, and no expectations means anything that happens has to be better than the bleak future he fears.

Or at least, that’s what Zichen tells himself.

“If this doesn’t work,” Captain Riker says, with a hint of steel, “we’ll keep trying. Somewhere, there _is_ an answer. This isn’t our last effort. But it is the last thing we can do from the Titan. We’ll deliver you back to Earth if this doesn’t work and put a larger team to work on it.”

What else is there to say? The meeting ends and the realignment team files out.

Yang sighs loudly. “Fuck, I should have saved the whiskey.”

Xingchen’s laughter sounds on the verge of tears, and Zichen takes his hand, kissing the knuckles. “Love, we’ll fix this,” he says, even though he knows it’s a lie.

Yang’s jaw tightens and he rolls his eyes, standing to leave, but as fast as a striking snake, Xingchen catches his elbow when he tries to brush past. With a yank and a kick, he pulls Yang onto his lap, wrapping his arms around Yang’s waist.

“Stop it,” he tells him firmly, like scolding a puppy. He tucks his chin over Yang’s shoulder, and Zichen wants to laugh at the shocked expression on Yang’s face.

“What shall we do for the next few hours?” Xingchen asks.

Zichen makes a suggestion before Yang can jackrabbit away.

“Risa?”

Xingchen grins. “Perfect. Let’s have a picnic on Risa.”

Yang opens his mouth like he is going to obstinately argue, so Zichen does the only sensible thing and leans forward, shutting him up with a kiss. He brushes his fingers over the high cheekbones and soft skin, pressing in until he feels Yang close his eyes.

“One day,” he whispers against Yang’s lips. “Just one day where you don’t say something that makes me want to throw you out of an airlock.”

“Don’t count on it, Song,” Yang retorts, but there’s a catch in his voice Zichen likes hearing.

And his name. Zichen likes hearing that, too.

For no good reason, no reason other than desire, he kisses Yang again, tilting his head back, slipping his tongue between Yang’s lips, intrigued by his sweet and salt taste. Xingchen rakes his teeth over Yang’s neck, and Yang moans into Zichen’s mouth. Zichen gives real thought to bending him over the conference room table to taste more of him, take more of him. His fingers itch to peel off Yang’s clothes…

Oh. No, his fingers itch. Literally.

“Fuck,” he has time to say, before

the pain

such breathtaking pain

pain that numbs him before it crushes him

“Xingchen? Yang?” he asks when his pieces seem reassembled again, taking long enough that people are pouring back into the room. He wonders how they knew. Did they hear him screaming?

“Leave me alone, I’m dead,” Yang-in-Xingchen says, and even though it hurts, Zichen laughs.

“Shut up, human,” Xingchen-in-Zichen scolds weakly, and Zichen laughs harder at the ache in his chest, at the irony, at the tragedy of losing so much he wants to keep, and he hardly notices when the laughter turns to tears.

★ ★ ★

Despite this inconvenient wrinkle, Captain Riker decides to continue on with the plan. There’s really no other choice.

After a few hours of medically-induced sleep, Zichen, Xingchen, and Yang file into the transporter room with two security officers and Commander Jaxa. Zichen is surprised that she sets a hand on Yang’s shoulder and even more surprised that he nods in deferential acknowledgement. When Yang catches Zichen looking, he casually flips him off behind her back, and Zichen has to fight not to laugh.

“Energize,” Lieutenant Commander Palmer says, and Zichen closes his eyes

When he opens them he knows two things.

First, he is not alone.

Second, he is inside...somewhere...and not on the surface of Kryal IV.

The first point is not as immediately frightening as the second. He didn’t expect to be alone. It only becomes bone-shattering terror when he realizes he must be on the alien ship because two of the aliens are walking toward him dressed in ornate black robes with gold embroidery that seems to dance and shift in the light, almost like it’s alive.

Zichen’s mind is spinning and he drops back, looking for a weapon—

_there is none, only an empty room, a room, not a transport pad, how is that possible, for that matter how are they here, stolen in transmission—_

looking for Yang and Xingchen—

_there to his left, and he moves, but Yang is already stepping in front of Xingchen, this is not their best configuration, Yang won’t be able to protect Xingchen in his body, but Zichen will never forget that he tried, a fierce welling of love he hadn’t expected—_

looking for an exit—

_none, no seams at all in this pale room with mottled walls that remind him of veins on a slab of blue cheese, which makes no sense, why would anyone build a ship that looks like this, it seems grown more than fabricated—_

when one alien, as huge and menacing as Zichen remembers, holds up a hand.

“Please. Wait. We won’t hurt you.”

The alien’s voice is beautiful, lilting and inexplicably harmonic, but Zichen knows better than to trust something just because it’s appealing.

“You attacked our ship and kidnapped us,” he snaps. “It’s hard to believe you don’t plan to hurt us.”

“We apologize for interrupting your transport. There was no other way to procure the Jiangzai. We did not _exactly_ attack your vessel. We attempted to target the Jiangzai for transport but your shields disrupted the calculations. Any damage was unintentional.”

What.

What?

The alien’s explanation makes sense, but Zichen still shifts to guard Yang and Xingchen. Not only is he the best equipped for combat, he is currently the ranking officer, and today that means facing down a demon. Even if the demon does seem polite and unusually friendly.

“I am Lieutenant Song of the United Federation of Planets. Who are you, what is the Jiangzai, and why should we give it to you?” he asks.

The alien—he has to stop thinking of them as demons—bows.

Bows.

Zichen resists the urge to bow in return.

“We are pleased to make your acquaintance, Lieutenant Song, although you seem to be only half of Song Zichen at the moment. We will rectify that. You may call us Tounao of the Tanxianjia, and they may be called Jiaoshou.” The alien, Tounao, waves a hand at their companion. “We are asking you to _return_ the Jiangzai, an artifact of the Tanxianjia. We are not angry about its theft, but it is too dangerous to be held by anyone other than the Tanxianjia.”

“Also, it is a _sacred_ relic of our people,” the second alien, Jiaoshou, adds, with a slightly reproachful edge to their words.

Zichen stares at them in disbelief.

“That is not who you are,” he growls, suspicious and defensive again.

Tounao shrugs, the casual gesture strange on their enormous shoulders. “You would not be able to understand our words so we borrowed descriptors from one of your languages. It has poetic layers reminiscent of our Yuyan.”

“I didn’t steal her,” Yang interrupts from behind Zichen, a mulish tone in his voice. “She chose me.”

Zichen closes his eyes. The knife. Of course.

“That is not a surprise,” Jiaoshou says. “You are sympathetic to her nature. You all are. The three of you presented her with an irresistible lure.”

“Yang,” Zichen says, turning to face him. “Even if you didn’t mean to take it, the knife is theirs. It needs to be returned.”

Yang refuses to look at him.

“You’ll still be a pirate even if you do the right thing,” Zichen says softly. “I won’t tell,” he adds with a smile when Yang gives him a sharp look.

“I hate you,” Yang informs him, holding out his hand. The black knife, now more of a short sword, is somehow already resting on his palm.

Zichen does not smile, although it is difficult. “I know,” he says, taking the knife, the Jiangzai, from him.

Before he can hand it to Jiaoshou, though, Xingchen asks, “What do you mean by irresistible lure?”

“We wondered that too, why she would so readily leave,” the alien says, and there is an excitement in their voice that makes their name seem aptly chosen. “It was not until we scanned your bodies, correctly paired with your consciousnesses, that we understood. You are an impossible convergence.”

The impossible convergence looks at each other in confusion and Jiaoshou folds his black-veined fingers together. “You see, the Xiao Xingchen is technologically altered, and the Song Zichen is ascension compatible. In combination with a sympathetic wielder, the Jiangzai’s dimensional chaos caused a tachyonic resonance during your transportation. The likelihood of you three being together on the same planet—”

“Such a remote planet,” Tounao interjects.

“—yes, such a remote planet during one of our rare cloistered communions, is so improbable, the odds make it virtually impossible.”

“What the fuck is ascension compatible?” Yang demands, and Zichen sighs. Trust Yang to pick out the one bit of information he would rather not discuss.

“Your human can explain it better, but it is a genetic predisposition to transcend mortal bounds and transform into a higher incarnation,” Jiaoshou says, gesturing to Zichen.

“Like...into a god.” Yang says, flat and cold.

“Oh, no, merely into a non-corporeal being of pure energy.”

“Oh yeah, big difference,” Yang retorts.

“It’s nothing,” Zichen interrupts. “Only a genetic maybe, like a late-in-life allergy to bananas. It’s nothing.”

“Zichen, it’s not _nothing_ ,” Xingchen admonishes. He sounds cool and distant too, and Zichen resents his DNA all over again.

“It _is_ ,” Zichen insists. “I didn’t even know about it until I joined The Academy—they test for it, you know, thank you Wesley Crusher—and every professor, every advisor, every captain has asked ‘but what if you ascend,’ and the answer is always I won’t, because you have to _want_ to ascend and I _don’t_. That isn’t who I am. I am a Starfleet officer. I am an engineer. I am the son of my parents, and I am the man who loves you.”

The words come out in an agonized burst. Zichen knows he’s begging, but he’s so tired of this...this thing that follows him around and makes everyone who finds out see him differently. It’s a part of him he can’t change, but he _has_ to believe he has control over who he becomes. He doesn’t want to warp space and time with his thoughts, or travel to other planes of existence. He just wants to live a normal life. Preferably in his own body.

“Precisely,” Tounao agrees. “But it is a trans-dimensional empathy Jiangzai could exploit. And so you find yourselves in this spatial flux. If you will please return Jiangzai, we will rectify her mischief and return you to the USS Titan.”

“And you?” Zichen asks, not quite ready to let go of their one bargaining chip, although he suspects the Tanxianjia could just take it. “What will you do?”

“We will restore Jiangzai to her qiankunju and go back to exploring our assigned dimension, as is our mission,” Jiaoshou says, holding out his hand. “If you please?”

Zichen looks at Xingchen and Yang. Xingchen nods. Yang looks mutinous, but eventually jerks his chin once. Zichen hands over the knife or sword or whatever it is. Jiaoshou spins the blade in their hand and it shifts, turning into a long spear, a two-bladed weapon, a spinning disk, a laughing girl with her finger to her lips. It all seems real and not, and Zichen is suddenly too tired to tell.

With a swift pirouette of their feet, Jiaoshou thrusts the weapon toward them. It shoots out a blinding star of light, and Zichen disintegrates into mist.

★ ★ ★

Whatever else the Tanxianjia may be, and later, Zichen sits through numerous briefings devoted to the subject, they are demons of their word. Zichen, Xingchen, and Yang are delivered alive and themselves to the Titan, amusingly deposited on the sparring room floor.

Zichen finds Xingchen’s hand and squeezes it, but Yang is up and out the door before either of them can reach him.

After so many weeks, they know the drill and head immediately to sickbay, calling the transporter room and tactical along the way. After a day of more tests than Zichen has ever seen, they are proclaimed healthy and their patterns are judged to be perfectly realigned. It takes two days to be debriefed by Captain Riker, Commander Jaxa, and Dr. Golwat, and then another day by the heads of Starfleet Science, Starfleet Tactical, and Starfleet security.

Xingchen is better at answering questions, so Zichen and Yang let him do most of the talking. Zichen spends most of his time staring at the table and thinking.

At night Zichen and Xingchen fall into bed exhausted, saving all their discussions for mornings. It turns out, they have quite a few things to discuss, including ascension, religion, genetics, and Yang.

“Zichen?” Xingchen asks one morning, before Zichen is actually, technically awake. “I’m going to get Yang now. Are you coming with me?”

Xingchen is always full of terrible ideas. Sometimes they’re terrible ideas like “let’s buy bags of candy for these random children I found” and sometimes they’re terrible ideas like “let’s find our prickly Orion and make him admit he loves us.”

Big or small, dangerous or not, Zichen is always along for the ride.

Despite the early hour, the ship’s computer says Yang is in Holodeck B. Zichen and Xingchen walk through the arch and enter an alien world, with a pale pink sky and bluish trees. Yang is sitting under a tree eating a fruit that looks a little like an apple, but he jumps up when he hears them.

“Why do neither of you have any manners?” he yells, but he doesn’t leave.

Zichen lays down in the grass and folds his arm behind his head. “Is this Orion? It’s pretty.”

Xingchen, however, prefers a more direct approach. He takes the apple thing away from Yang, tosses it on the ground, and drapes his arms over Yang’s shoulders, kissing his forehead. “I’m keeping you, I think,” he says.

For once, maybe for the first time in his life, Yang is utterly speechless.

It doesn’t last.

“What the fuck does that mean?” Yang pushes Xingchen away, and there’s a panicked, confused look on his face that a wicked part of Zichen profoundly enjoys.

“It means, you idiot, that he likes you,” Zichen says, sitting up, and Yang glares at him.

“And you’re just fine with that? Gonna let your beloved Bajoran fuck me whenever he wants? Doesn’t that make _you_ the idiot?” Yang’s lip curls in a taunting sneer, but his eyebrows are still locked together in apprehension.

Zichen laughs. “I love him, I don’t own him. We’d like to love you too, if you’ll let us.”

Yang stares at him, jaw clenched so tightly, Zichen can almost hear his teeth grinding. He grabs the backs of Yang’s knees and pulls him down onto his lap. He knows the answer is yes, because if the answer was no, Yang would already be gone. But he wants to tell the whole truth.

“ _I’d_ like to love you,” Zichen says gently, smoothing his thumb over Yang’s lips. “If you’ll let me.”

Zichen brushes back the hair from Yang’s forehead, looks into the green-black eyes, and he waits. He kisses the corner of Yang’s mouth lightly, in his own body, with his own intent, and he waits. He runs his hands down Yang’s back, splaying his fingers over his waist, and he waits.

Finally, _finally_ Yang chooses, cupping his hands around Zichen’s face and kissing him. He hums, a little noise of contentment, and it’s almost enough to make Zichen flip him into his back and ravish him right here in the holodeck, but he wants to hear the whole truth too.

He nibbles Yang’s ear.

“Say it,” he whispers.

Yang refuses, but he does tilt his head so Zichen can taste the line of tight muscle on his neck.

“Say it, Yang,” Zichen repeats.

“Fine, yes, fine! He’s…” Yang whimpers as Zichen kisses the dip at the base of his throat. “He’s unreal and you’re awful, and I fucking love you both. Happy now?”

Zichen had only been expecting the yes, and now it’s his turn to be speechless. He looks at Xingchen, who gives him a very silly smile, a smile Zichen suspects is reflected on his own face.

“Xingchen?” he asks, and Xingchen’s grin widens.

“Zichen. Yang.” Xingchen squeezes Yang’s shoulder. “Let’s go home.”

They are only barely back in their room before Xingchen is undressing Yang, kissing the arch of his shoulder, the curve of his bicep, the pulse point of his wrist. Yang inhales almost painfully and bites his lip when Xingchen lifts his hand.

“This too,” Xingchen murmurs, touching his lips reverently to the missing space of Yang’s pinky. “Too.”

Yang looks like he might cry, and he seems poised for flight, so Zichen distracts him by kissing his mouth, dragging his fingers across Yang’s jaw. Yang tips his face up to Zichen, and his trust, his willingness to be distracted, ties a tight cord around Zichen’s heart, next to the one that belongs to Xingchen. Eventually they’ll talk about the pinky, the scars on his back, the lines on his arm, about _escalating pain_ , but maybe not today. Zichen doesn’t think he can take it today. He just wants love today.

Zichen swiftly shrugs off his jacket, shirt, and pants before he sits on the bed and pulls Yang on top of him, startling a yelp out of him.

“Which part is so awful?” Zichen asks, unbuttoning Yang’s pants and sliding his hand down them.

Yang groans and tips his head against Zichen’s shoulder. “You want to talk about this now?”

“Is it my hands?” Zichen persists, stroking Yang, and Yang pushes up into his palm.

“Fucking...fuck, Zichen, no, it’s…” he stammers, and Zichen grins.

“Is it my mouth?” he tries again, sucking on the pale green lobe of Yang’s ear.

“A...little…” Yang admits between ragged breaths.

“I find your mouth practically intolerable,” Xingchen agrees, leaning down to claim it, stealing away Zichen’s breath and heart.

Xingchen is entirely naked now, so beautiful and confident, he’s almost too difficult to perceive. Zichen dances fingers over his hip, wishing he could do more.

“Yang,” Zichen whispers. “Will you suck Xingchen for me? I can’t reach.”

Yang huffs derisively, but he tentatively touches Xingchen, who exhales like a battle has been won. He leans forward, licking the ridges curiously, more purposefully when he hears Xingchen’s reaction, before sliding the cock in his mouth. Xingchen closes his eyes, rocking with the momentum of Yang’s mouth, running his hands over Yang’s face, his shoulders, his neck, committing him to memory.

Zichen is mesmerized watching them, listening to them, and he tries to understand how they can be so perfect as two and so perfect as three. The math doesn’t seem to support the conclusion, but the evidence is irrefutable. Sometimes desire can’t be calculated.

He lets go of Yang, despite the grumble he gets, and finds the lube. He kisses a path down Yang’s back, the knobs of his spine, the faint white lines, before he asks. He doesn’t really _want_ to ask, he just wants to _have_ , but it’s new, this is all so new, and the scars make him feel he _needs_ to ask at every step.

“Is this okay?” Zichen manages, not spectacularly eloquent.

Yang sits up and kisses him with the taste of Xingchen in his mouth.

“It’s okay,” he says. “It’s all okay,” and Zichen is suddenly wild and desperate.

Not as gently as he’d intended, not gently at all, actually, he pushes his fingers inside Yang, feeling the soft core of him and reveling in the way his back arches, the way he slams back against Zichen, the way he whines and clutches Zichen’s thigh. Is _this_ who he is, Zichen wonders, not the flippant sneers and sharp edges?

And then Xingchen is there, kissing Yang hungrily, biting and rough, and Yang is touching him again, stroking a hand along his cock, and they are moving together, all three of them, sound and touch blending them into one. It’s really only a slight adjustment, just the barest hint of movement for Zichen to shift Yang’s pliant body, to tip him forward, to thrust into him, to bury himself in heat that feels like the end of a journey.

“Love you, pirate,” he gasps, “like it or not.”

“Fuck you, human,” Yang says pleasantly before devouring Xingchen’s cock again, noisy and eager, and Zichen laughs, because what did he expect? For that matter, what else would he want? Yang is both things, obstinate and yielding and Zichen wouldn’t want him any other way.

His climax is a rolling wave of destruction, vibrating through his fingers and toes, even to the tips of his ears. Zichen clings to Yang’s waist like a lifeboat in a storm and Yang leans back, winding his arm around Zichen’s head, anchoring him until the shuddering subsides.

Zichen falls back onto the bed, carrying Yang with him, laughing when Yang hooks his foot around Xingchen’s leg and drags him along too. Xingchen lands on hands and knees and kisses them both before he gently nudges Yang to his back.

“Alright Xiao, so pushy,” he protests, but he wraps his legs around Xingchen’s waist, just as impatient. Impatient, but still pathologically contrary.

Zichen caresses Yang’s face and kisses him when Xingchen enters him. Yang’s body stiffens, and he inhales sharply against Zichen’s lips. It’s different, Zichen knows, and he can’t tell immediately if Yang likes it until he exhales, a tremulous _oh_ , and Zichen smiles at the wide eyes and heavy, panting breaths that sound almost ripped from him.

“Oh fuck, Xingchen, please, fuck, I can’t, I need, I... _more_...” Yang chants, the words blurring into nonsense.

Zichen loves watching them, loves seeing Xingchen demanding and Yang giving. The second Xingchen’s bites his lip and tips his head back, Zichen wraps a hand around Yang’s cock, moving in strong, decisive strokes. Yang keens his name, hands scrabbling at the bed, at Zichen’s arm, at Xingchen’s hands on his ass before he is coming, crying out and rutting uncontrollably into Zichen’s hand.

“You fucking asshole,” Yang hisses, pulling Zichen’s hair until he can kiss him, tears leaking from the corners of his eyes.

Xingchen collapses next to Yang, and Zichen instinctively reaches for him, running a hand along his side and across his back. Xingchen folds Yang’s limp body into his arms and nuzzles the space behind his ear.

“Still okay?” he asks, and Yang nods, closing his eyes.

“You guys are weird,” he mumbles. “So many questions. Is it okay? It’s fucking phenomenal. You don't have to keep asking.”

But a pleased smile curves the corners of his lips, and Zichen thinks he _is_ going to keep asking, especially if he keeps getting that smile.

After Zichen finds a towel and cleans them, ignoring Yang's protests, Yang nestles against Xingchen and pulls Zichen closer. Zichen rests his forehead against Yang’s, basking in the warmth of peaceful, dreamless sleep.

He wakes when Yang slides out from under his arm.

“Are you leaving?” Zichen asks sleepily, watching Yang put his clothes back on.

Yang pauses and sucks in a breath. Still preparing for an attack, Zichen thinks.

“I just…don’t always like to fall asleep...around other people.” Yang lifts his chin, daring Zichen to disagree. He looks nervous, though, and it’s hard for Zichen to soften his expression and let him go instead of tucking him safely between them like he wants to.

“Okay,” Zichen says with a crooked smile. “Will you return later?”

Yang grins. Is it the first time Zichen has seen him smile like that? Spontaneous and full? Like he means it?

“Yeah,” he says with a little laugh. “You’re mine, and I’m not giving you back.”

★ ★ ★

And then, there is the rest of their lives.

They do their jobs. They get promotions. They see their friends in Eleven Aft and in the training rooms. They make new friends. They get a bigger bed, and some nights Yang stays with them, more and more as the years go by. Some nights he doesn’t, but as promised, he always comes back.

Xingchen decides he wants to learn to sword fight, and neither Zichen nor Yang argue, although they share a look that wonders at the wisdom of handing a blind man a sharp object.

He is, of course, a natural, almost preternatural, and Zichen and Yang privately agree it’s a good thing they never seemed doubtful.

Zichen sometimes feels the tingle of—something else. Another existence, another dimension, another possibility tickling the back of his mind, the laughing girl always waiting, ready to be invited.

He pushes it away. His life is here. Normal. Now.

They use their shore leave to travel. Back to Earth to meet Zichen’s family. Out to Bajor with Xingchen to meet Ambassador Baoshan, his foster mother. And sometimes they go wherever Yang wants, since he doesn’t want to visit Orion. He particularly likes Nibiru, with its red flora and calm oceans.

They stand on a cliff under a scarlet tree and watch giant fish leap from the water, crashing down in a spray of sparkling drops, for hours before Yang leans against Zichen’s shoulder. The rhythm of water and wind is always a balm.

“Okay,” Yang sighs, and Zichen kisses the top of his head.

“Come on,” Xingchen says, sliding his arm around Yang and fitting his hand into Zichen’s. “Let’s go home.”

 _We’re already home_ , Zichen thinks, following Xingchen and Yang back to the pattern enhancement beacons. Home is _here_. Yes, home is a ship. Home is a room. Home is space and the wide open sky. But most of all, home is wherever they are.

Together.


	2. vinculum: The Background

**Summary for the Chapter:**

> Because Star Trek is such a detailed existing universe, I thought I should explain some of the references and decisions in this story. My great thanks to decades of devoted Star Trek fans for having some of the most detailed and beautifully organized fan websites. Any mistakes or alterations are entirely my own.

**Some Basic Background:**

According to [Memory Alpha](https://memory-alpha.fandom.com/wiki/Portal:Main), the United Federation of Planets is an interstellar union of planetary governments that has agreed to exist semi-autonomously under a single central government.

Starfleet is the deep space exploratory and defense service maintained by the United Federation of Planets. Its principal functions include the advancement of Federation knowledge about the galaxy and its inhabitants, the advancement of Federation science and technology, the defense of the Federation, and the facilitation of Federation diplomacy. There are both commissioned and non-commissioned ranks in Starfleet. To make it easier, everyone in this story is a commissioned officer.

This story takes place entirely in the Alpha Quadrant, which is the quadrant of the Milky Way that Earth and most of Federation space exists in. However, the previously-unencountered alien species is not native to the Alpha Quadrant (see below).

The USS Titan is a 450m Luna-class ship with a crew complement of 350 (100 commissioned officers and 250 enlisted crew) and is intended to be an extended-mission, deep-space explorer. It is a newer ship design and tactically advanced. Only 15% of the Titan’s crew is human. By comparison, the USS Enterprise-D, Jean-Luc Picard’s Enterprise, is a Galaxy-class ship, and is 642 m with a crew of 1012 (and space for 200 passengers). If you want to learn more about Star Trek starships (and I do mean more), everything you ever wanted to know can be found here: [Tech Specs](http://techspecs.acalltoduty.com/luna.html).

**Main Characters Background:**

**Song Zichen** , Lieutenant, human, assigned to Engineering: You may already be familiar with humans. Ascension to a non-corporeal energy being is handled several different ways throughout the Star Trek universe shows, most notably with Wesley Crusher and the Bajoran Prophets. It is sometimes viewed as an evolutionary process, a spiritual potential, or due to alien genetics.

 **Dr. Xiao Xingchen** , Lieutenant Junior Grade, Bajoran, assigned to Medical: Bajorans are a humanoid species native to the planet Bajor in the Alpha Quadrant. Bajor was under the rule of another species, the Cardassians, for around 50 years before the Cardassians withdrew from the planet in 2369. Bajorans are considered independent of the Federation at the time of this story, so they are not common in Starfleet. Bajorans are, as a species, deeply religious. Their religion centers around the Prophets, a non-corporeal and somewhat god-like alien species. When not in uniform, they wear a complex, multi-tiered earring that signifies their faith. Bajorans have a distinctive set of four to seven nasal ridges. Although the penile ridges are not canon, they are apocryphal. Bajorans are a significant part of the show Star Trek: Deep Space 9, so I stuck to existing facts.

 **Xue Yang** , Ensign, Orion, assigned to Security: Orions are a humanoid species from the Alpha Quadrant. In the Star Trek universe, Orions were considered neutral for a long time, but are not anymore due to the Orion Syndicate, a crime organization that is believed to still exist, although very little is known about it. Orions are most recognizable for their green skin. Female Orions often exude pheromones that have the ability to impact males of other species, which allowed Orions to take control of their ships. Less is known about male Orions. Although they were once the dominant gender and subjugated female Orions, it is believed that at some point, that role was flipped and men were made slaves to the women. I made up a lot of details about Orions because there aren’t many known facts, just a lot of conjecture.

 **Lan Wangji** , Lieutenant, Vulcan/human, assigned Senior Conn Officer: Lan Wangji is the primary flight controller and navigator for the Titan. Lieutenant is the minimum rank for the senior conn officer, and Lan Wangji is a bit of a piloting prodigy.

 **Dr. Wei Wuxian** , Lieutenant Junior Grade, Bajoran-raised-human, assigned to Science: Wei Wuxian was the son of Bajoran scientists who were killed on a mission. Their distress signal was picked up by a nearby Federation science vessel, and Wei Wuxian was raised by the captain and his wife.

**The Rest of the Named Crew:**

You may notice that everyone in this section, with the exception of Will Riker, is female, and several are retconned from death. That isn’t an accident.

Will Riker, Captain, human, assigned Titan's Captain: Riker became captain of the Titan in 2379, so this story takes place sometime after that.

Deanna Troi, Commander, Betazoid/human, Counselor: Counselor Troi transferred to the Titan in 2379 after marrying Will Riker.

Nidani Ledrah, Commander, Tiburon, assigned Chief Engineer: I retconned Nidani Ledrah, chief engineer of the Titan, who was killed in 2379, and I gave her a promotion.

Sito Jaxa, Commander, Bajoran, assigned Chief Tactical Officer: I retconned Sito Jaxa, who was killed in Star Trek: The Next Generation, and I gave her several promotions. Tactical is in charge of security, weapons, shields, and communications.

Dr. Golwat, Commander, Bolian, assigned Chief Science Officer: I promoted her from Ensign in Star Trek: Voyager to Commander and Chief Science Officer. Bolians are blue and have interesting cranial striations.

Mae Palmer, Lieutenant Commander, human, assigned Transporter Chief: Palmer is a character from Star Trek: The Next Generation, played by Mae Jemison, a real life astronaut. I gave her a promotion and a first name, which she didn’t have in the show.

Dr. Wen Qing, Lieutenant Commander, Romulan, assigned Chief Medical Officer. Wen Qing and her brother, who does not appear in this story, were raised on Earth, descendants of a family who worked at a long-ago Romulan embassy on Earth. Very few captains would be willing to take on a Romulan officer, even if she is the best doctor in the galaxy (according to her brother). I took a leap with this backstory, although the history of Romulans having an embassy on Earth is part of two movies. The Romulan relationship with the Federation is...tricky. 

Luo Qingyang, Lieutenant, Klingon, assigned Senior Security Officer.

Ambassador Baoshan Sanren, Bajoran: Some Bajoran ambassadors are religious leaders known as Vedek, but Ambassador Baoshan, Xingchen’s adoptive mother, is a political appointee. Despite her status as an ambassador, she is something of an eccentric and prefers to live on Archer IV, an uninhabited planet, unless required by either Bajor or the Federation.

**Naming Conventions:**

I agonized over this and eventually just had to come to a decision. I left MDZS names as is to avoid confusion, although I used Federation-typical styling in the way the characters refer to each other. I’m going to blame the universal translator and the fact that Song Zichen is Chinese, so these conventions are unique to him and the way he is hearing the language.

For example, Xue Yang is still Xue Yang, even though he’s an alien, but it’s not strange for him to be called by just his last name, Xue, as many Starfleet officers refer to their friends, or Yang, as many people refer to their closest friends.

Occasionally people are referred to by their assigned position, when it’s important to note, but more often they are referred to by their rank. Someone would refer to a higher-ranked official or someone they aren’t friends with by their rank and name. But there’s also personal preference. In Star Trek, Will Riker is referred to by almost all of his friends as Riker, and only rarely as Will.

For example, Zichen refers to his boss as Commander Ledrah, although they are more-or-less friends. He is good friends with Wei Wuxian, so he refers to him by first name. He is not friends with Xue Yang at the start of the story, so he refers to him by rank and last name.

**Planets Mentioned:**

Kryal IV and Yecal VI are entirely fictional. The number after the name indicates its position from the sun in its system. Kryal IV is the fourth planet from the sun (or two suns, in its case).

Nibiru is from Star Trek Into Darkness.

Bajor is the home planet of the Bajorans.

Orion is the home planet of the Orions.

Risa is a popular tourist destination mentioned in several Star Trek series.

**The Tanxianjia, aka, Species 8675:**

Not much is known about the Tanxianjia. They are a trans-dimensional species, not from the Alpha Quadrant. Their ship is biological rather than mechanical (I borrowed these ideas from Species 8472, a species encountered in Star Trek: Voyager, and Moya, the ship from Farscape). They are somewhat telepathic and used Zichen’s first language to assign themselves names they felt captured the descriptive layers inherent in their own language.

The Tanxianjia are close to 7 feet tall with red skin, black horns, and fangs. They look very similar to the Earth concept of demons. Despite their appearance, they are a peaceful species, explorers, and guardians of the Jiangzai.

Tanxianjia: tànxiǎnjiā, 探险家, explorer, adventurer

Tounao: tóunǎo, 头脑, brains, mind (colloquial: chief)

Jiaoshou: jiàoshòu, 教授, professor

**Sundries:**

Cetacean Ops: The USS Enterprise-D had cetacean ops facilities, including a cetacean navigation lab and four cetacean lifeboats. It’s hard to say if the Titan does too, but since no one has denied it, I’m giving them dolphins at least.

VISOR: Stands for Visual Instrument and Sensory Organ Replacement. It is a medical device used to aid people who have lost their eyesight or were born blind. It was most famously worn by Geordi La Forge on the USS Enterprise, although there have been other background characters seen wearing VISORs. The VISOR allowed the user to “see” in infrared, ultraviolet, thermographic, and more, via electromagnetic impulses. It is a very useful tool at times, but also physically taxing on the wearer. It is unusual for the wearer to fully integrate with the VISOR as Xingchen has done.


End file.
